This is an index of tropes that are often indicative of plain bad writing.
When done unintentionally, these tropes are usually bad signs. When done intentionally, they're often signs of parody, comedy, or just the writer being ironic or stylized. Hopefully...
Jerk Sue: Having a character be a complete Jerk Ass who gets away with it just because the author designates them as such and says you should support them does not make for a strong character, and is more likely going to turn out be a case of Creator's Pet, and often The Scrappy. Also, it tends to look like a half-assed effort when the author just throws in some secondary throw-away detail in an attempt to make you feel sorry for the character and expect you to not get upset when they behave like a jerk for no other reason than they feel like it at the time.
Villain Sue: A flawless, invincible villain who never loses at anything makes for a boring story just as much as an ordinary Mary Sue.
Wangst: Make your characters react realistically to setbacks or tragic events. Too much angst makes them unrealistic and annoying.
Wimpification: Stripping the action, common sense, and characterization from a male character to add Wangst and gender stereotypes applied to females is a good way to piss off many of the audience, including but not limited to feminists and actual gay or bisexual men.
Idiot Plot: Unless it's part of their character, the plot should not be forced to move forward solely by people making stupid decisions.
It Gets Better: Just as the viewer shouldn't demand the work to end already as with Ending Fatigue, they shouldn't be forced to sit through hours of exposition or padding to get to the actual plot.
Just Eat Gilligan: If there's an obvious solution to the problem(s) that drives the story, you would think the characters would go for it rather than ignoring it.
Kudzu Plot: It's fine to have a dozen different story threads at once, but you have to be able to tie them together. If they go off into infinity without ever being tied, who's going to care about any of them? The pieces of your Jigsaw Puzzle Plot have to fit.
Offstage Villainy: We need to see that the villain is evil. Being told so doesn't automatically make him/her "evil".
Author Filibuster: The reader/viewer/player/etc is (theoretically) interested in the plot. Stopping it so that you can talk about something that's important to you will only make them less interested in what you're writing.
Examples Are Not Recent: When writing an example, avoid using the word "recent." What's considered recent now won't be in a couple of years. It just makes more trouble for other tropers to edit out the word "recent" once it isn't recent anymore. Act as if every work that was ever published came out several years ago.
Square Peg Round Trope: Make sure that the example that you want to add fully fits the trope. If it's "not really an example", then it's not really an example, and it shouldn't be added.
This Troper: Writing about oneself in a Main wiki article. The goal is to make Main articles sound like a single person is editing the article, not multiple people. Besides, personal comments just clog up the articles.
Thread Mode: Don't clog up a trope entry just because you don't understand why it's there.
Type Labels Are Not Examples: Any relevant context needed to explain the example should be given in the example itself. Don't simply label it "type X" and force the reader to open a separate page just so they can understand what it means.
Weblinks Are Not Examples: If one has a trope example, one should write it down, in adequate detail, where it is relevant, not rely on a URL link to some other page to explain what it is.
Word Cruft: When writing an example, just stick to writing the example and try to avoid saying useless things that don't need to be said.
As a note, most of the stuff here can, technically, fall under Sturgeon's Tropes in regard to music. That said, these are listed here because its failure (and making its song/lyrics fall flat) is far more common than its success - and even the successes are generally not considered the best songs of their genre/band/etcetera. Overuse is often what moves these from "Sturgeon's" to "bad" territory: no one really minds, for example, if the singer has a Lyrical Tic of "Oh yeah." If, on the other hand, the singer is screaming "Oh yeah let me hear you" over every single guitar part, and gets literally thrown off the stage by the guitarist(s)...
Contractual Purity: Despite the common and widespread use of this (especially in South Korea and Japan, and for Disney starlets in the US), enforcing it pretty much sets up the artist for unrealistic expectations and failure. Even setting aside the Unfortunate Implications and Double Standard of its application being primarily to women, a very important part of writing original lyrics/music and maintaining verisimilitude rather than "who really wrote this for her," is life experience - which, yes, can include the very things Contractual Purity forbids. Another problem with Contractual Purity is that it creates such conditions as to encourage people who break it to go Off the Wagon with Sex Drugs And Rock And Roll when they do, and at the same time, sets up the media to come down on them as if they'd done the most awful thing possible - often destroying their careers as artists in the process.
Kids Rock: Often seen as a mawkish, overwrought attempt to draw out emotion, or, depending on the lyrics and atmosphere of the song and/or the style of the artists, just plain creepy.
Gratuitous English: Randomly popping in meaningless English words that you don't know the meaning of is a bad idea. That's not to say that non-English speakers shouldn't sing in English - there's plenty of good songs that have dual-language lyrics, just know the meaning of your English, make sure it's somewhat grammatically correct, and that the syntax and usage match.
Gratuitous Japanese: This one is, on the other hand, almost always bad, because it's primarily used by the Occidental Otaku and right out the gate cheapens your work and pigeonholes it to that demographic, as well as being seen as potentially offensive mockery of Japanese artists who use Gratuitous English. If you are not a very high level (native or the highest level of the JLPT) Japanese speaker, it is generally not a good idea to use random Japanese in your music. Either make the entire song in Japanese and learn how to properly pronounce and sing it, all the while working with a native speaker or high-level speaker, or just write it and sing it in your native language. And whatever you do, leave the "sakura," "kawaii," "baka" and other "anime Japanese" out of it unless it's a parody.
Gratuitous Rape: Deserves a second special mention here. If you are going to address the topic of rape in your lyrics, address it in some meaningful way and be ready for the consequences.
Last Note Hilarity: Unless you are a comedy/parody act, you don't want the audience to laugh at your music.
Last Note Nightmare: If done for effect, this is fine. If done unintentionally, then you've probably made a big mistake.
Lyrical Tic: Don't rely too much on these. They annoy some listeners pretty fast (and some, especially of the "Whoo hoo" variety) are cliches. Not to mention that many listeners (not to mention the other band members) see them as filler and wish the vocalist would just shut up if he or she is overusing these.
Mad Lib Metal Lyrics: Not necessarily bad in and of themselves, but often indicative of laziness or sloppiness if overused.
Music Is Politics: Yes, in some ways it is. That said, tying your work specifically into party politics (e.g. explicitly supporting/attacking a political party by name) tends to make it an Unintentional Period Piece and cheapen it.
Painful Rhyme: Don't force rhymes. If something doesn't rhyme, you can make a non-rhyming song that can be just as good as a rhyming one, or try to find rhyming words that both describe what you want and rhyme.
Rated G for Gangsta: Making your music Lighter and Softer / less profane or violent / more "religious" may be a good decision, but keep in mind it may not be, and doing so will anger the fans who enjoyed your work because of its less worksafe/family-safe themes, possibly enough to lose them as an audience.
Something Something Leonard Bernstein: Depending on your genre, this might actually be workable. But in anything requiring "clean" vocals (e.g. not "clean" as in lack of profanity but "clean" as in understandable) this is automatically bad, and even in more permissive genres overly relying on it is often a bad idea.
Standard Snippet: Sometimes can be put to good use, but often becomes a cliche. If your work is heavily reliant on remixing or sampling, try to find stuff that isn't used all the time and by everyone else - unless you have a very good reason such as parodying the rampant use of the Standard Snippet.
Vocal Range Exceeded: Don't write things your singer can't sing, and if you're the singer as well as the writer, be realistic about your range and capabilities. note A common mistake here is writing for the highest ranges such as pure soprano and alto. Especially among male singers, the capability to reach these ranges is vanishingly rare, and even most female singers fall short of being capable of pure soprano or alto voice, and a singer who is incapable of such and tries anyway will likely sound falsetto and possibly damage their vocal cords.
Canon Defilement: People who are reading your Fan Fic probably enjoy the show for what it is. Not for what you would like it to be. Seeing beloved characters mangled into whatever form you desire is probably going to cut down on your audience, unless you're Neil Gaimannote And even he shows a great deal of respect for Canon while mangling it.
Dan Browned: If you haven't done the research, don't claim you have.
Demonization: Some of your potential audience may actually see where this position is coming from, if not actually agree. You'll turn them off by your exaggerated portrayal. It also makes it seem like the position you hold isn't nearly as solid as you think, since it can only stand up to strawmen.
IKEA Erotica: Sex should only be as boring as it is to the participants.
I Suck At Summaries: If you can't be bothered to summarise your fic properly, then why should people be bothered to read it?
Narm (when caused by the writing): Make your dramatic/climactic scenes convincing, not cheesy. Don't go over-the-top. Make it realistic. Think about how a person in Real Life would behave in the situation.
Nightmare Retardant (when caused by the writing): If something is supposed to be scary, either don't show it or actually make it scary.
Strangled by the Red String: People going directly from being strangers to being genuinely in love is not very realistic or satisfying to watch. If you're going to make two characters fall in love with each other, try to take it slow.