Play higher ttk games like quake or overwatch. It will most likely improve your aim on static clicking based games like cs and val although it won't matter if you don't work on your gamesense.
yes, you will improve aim but if you reallly wanna get better aim and not just play boring aimtrainers like losers, then u should play some high ttk games like overwatch and just only play hitscans chars like ashe, cassidy, and widow