Try Commands below to practice:

sv_cheats 1; sv_infinite_ammo 1; sv_grenade_trajectory 1; sv_grenade_trajectory_dash 1; sv_grenade_trajectory_thickness 1; mp_roundtime 60;mp_roundtime_defuse 60;mp_restartgame 1

bind 'key' noclip //toggle this command to go through walls to see your nades go.


Subscribe and try the maps below:

training_aim_csgo2
Fast Aim / Reflex Training
Recoil Master - Spray Training