Putting in cameos from other works, (your own or theirs)

I'll go straight to the question. How far can you go with putting in cameos from your own or other peoples works? Whether as a background character, or an AU version that might have a role? I feel like I don't want to put in too many cameos because, A) I might get people confused if every single piece of work is connected to each other, in the same universe or timeline. and B) even if the cameo is from a piece of work from somebody I have a close relationship with, it's likely that one day either of our works are copyrighted and published publicly, and I either have to take great pains to get the rights to still use the cameo, or replace the cameo with something original. Now even if the later situation isn't the case and I just make references to my own previous works, from a storytelling stand point it might be lazy if one character is called Sam Haroldson in one story, and another character of the same name in a completely different story.

I think the best way to go about this is look at other works and see how far they go with there cameos and shout outs.

I'd start here and see what other guys get away with.