Personally I've been having trouble sticking to one specific way; I keep switching from resting my arm on my chair-rest and using only my wrist to aim, to putting most of my arm on the table, to putting my arm and elbow on the table. And I'm aware all this switching and not sticking to one routine is probably detrimental to my gameplay.

(And incredibly uncomfortable and annoying too.)

Does anyone have any tips or suggestions? What do most pros/high-ranked players use?

I'm aware it's a somewhat basic (and to some, useless question but I'd really appreciate some input here, especially so I don't accidentally develop carpal tunnel or some such wrist injury.