Embedding posts that aren’t the current post

Hi!

I need to have a ‘related posts’ element on my single template, but don’t know how to effectively execute it. These posts can be random, but if it’s possible to specify, that would be great too, as long as they’re not the post you’re on.

Say you’re on post #1, then I want post #2, #3 and #4 to be visible on the related posts element. If I’m on post #2, I need post #1, #3 and #4 to be shown.

Thanks in advance!