The former Chief of Disguise for the CIA was interviewed about how you can change your mannerisms and clothing to escape notice. Some people rely on this in-game so I'm linking to the video for them to check out. Enjoy!
I posted this before the disguise update came about, and now feel this is waaaay more helpful for people who want to take their disguise rp to the max.
I've been trynna incorporate some of these myself after I watched the video. Not just for disguises, but in general actions and body language. Good post.