watch demos of tpn runs, watch demos of yourself, pay attention to the damage markers, and dont throw your mouse/aim all over the place focus on it ! and speedrun (even though i hate it and dont do it cause it makes hate the maps where i try it ... it definitely helps with consistency)
also high sensitivity it definitely hurts most people, not all of them, this game has way too much ppl playing with shitty sens like 2 inch/360, it works for some ppl but it hurts more imo