AO3 Guide - Switching and Crossposting

As someone who uses the big 3 Fanfiction sites, I've noted that many Wattpad users flock to AO3. Said users have no idea what they are doing and are even unknowingly breaking Terms of Service of AO3.

So I, someone who already switched, albeit not abandoned Wattpad, decided to make a guide, so that r/AO3 on Reddit gets a break from idiot users who can't (or just won't) read the TOS.