The answer is practice and study. Practice describing all kinds of things. Describe your favorite coffee shop or other hangout, your workplace or a classroom of your choice from school or college, your bookshelf, a favorite meal, your pet(s), an outing with friends or family, your neighborhood in a storm. Imagine you're describing those things to a new friend, a young child, a senior citizen, a pen pal from another country, one of your story's characters (I'm guessing they're not familiar with modern Earthen culture), a space alien trying to learn about Earth culture and society. Go get your favorite books and study the descriptions. Think through how they paint a picture in your head and how they make you feel about whatever's being described, and what lines and phrases do what. Also do some actual historical and factual research into things you want to include in your story so you can give your descriptions more detail and make them feel more lifelike.
It looks like you're having trouble with simply getting your words to convey the information you want, though. If you mean to say that the castle is not within the forest, ask yourself- what's between the castle and the forest, then? Assuming your setting is medieval, I think it'd make more sense for a castle, whose primary purpose is to protect the people living in it, to be placed a good distance from an unguarded forest, because even a moderately heavy forest can hide a whole army of enemies and the castle guard would want enough time for them to barricade the gates, and rally the men and get everyone geared up to defend the castle before the bad guys show up.
You could make a mention of the trees gradually thinning out enough to see the sky between each one, or the forest just stopping because the king had some of the trees cleared away, revealing whatever is between the forest and the castle. Probably flat open ground that'll take some time to cross and the occasional village or homestead, where maybe your characters can buy some food, get some supplies, or sleep indoors for once before getting to the castle. If you have a clear image in your head that just isn't coming out right, the first thing you should do is make sure you're considering all possible details that are making the image logically connect for you. Sometimes you need to walk away from it and think about something else- even just messing around on your phone for a few minutes can do it. Perhaps when you were picturing the area, it was meant to be "there's nothing of real interest between the forest and castle", your brain turned it into "there's nothing between the forest and castle", and it wound up on the page as "the castle is in the forest".
From there, you can try thinking about what else you want the reader to know about whatever you're describing. Remember that description is more than just stating the facts about what something's like. You can have your descriptions perform double duty and show not only what something is like, but what the characters think of it, and in the process, their characterization. Maybe they're intimidated by the royals, and so describe the castle as looming, or stately, and focus on all the things that make the castle scary or like it's removed from its subjects. Maybe they're unimpressed and allude to the castle sitting pretty and useless like a crown jewel or ancient and obsolete, making note of its useless ornamentation that probably cost enough to feed their whole family or an entire village for a month, and by contrast describe the settlements along the way as bright and vibrant and more "real". Maybe the characters are excited because they're from a backwater village, and admire how pretty the castle is and how neat all of the ornamentation is. Have fun with it!
Edited by CrystalGlacia on May 17th 2020 at 10:28:57 AM
"Jack, you have debauched my sloth."
i am struggling with describing things.. like- i want to say that theres a forest that our Good Boys must traverse through to get to a castle, but the way i'm describing it feels like the castle is in the forest... how do you achieve a 'good' description.. thingie.. scene?