[Half-Duplex]

The best thing you can do to get better at sniper is play nothing but sniper.

You learn your own "tricks" along the way, as with any class.

Edit: As for the commands, I think what you're talking about is one of the CL_ commands if I'm not mistaken. It alters something with your lag compensation vs the hitbox of your opponent. Won't go much into detail as I don't have the command written down here at work and I don't feel like doing the research.

But there is some command that "helps".