Watch these guys:
Voo_csgo - best for getting better, and fixing your mistakes, best channel out there
Elmapuddy - Breaks down pros, good for learning pro habits and thinkings
mfknbruno - Good for fixing your mistakes (got you bro)
Hawka - Similar to Elmapuddy
Mahone_tv - Best for upcoming teams trying to learn pro execs and setups
If you want to get better watch these guys, especially voo, watch all of voo's videos.
Furiouss aim trainer video - Personal experience, it's the only method that has gotten me good aim, but you could develop shaky aim.
Launders - sometimes he can be a hit or miss, but can break down pros demos