Signs when your guy/girl bestfriend likes you

So basically I'm going to write this book or should I call a list or whatever, to help you guys with your problems or questions and if you guys ask me why I know such a thing because I've been in this situation before but moving on. If I'd get 20 or more reads, comments and of course favs I'd do another one like this and if you guys have some problems just DM me or comment and I'll try to make some guides about it.