Condoms and foreskin.?

Ive read that you have to retract your foreskin then place the condom on, then roll the foreskin back over the tip of penis. however, when i tried to roll foward my foreskin to cover the tip of my penis after the condom is already on, i have so much trouble doing it! i have trouble rolling my foreskin over the tip of my penis once the condom is already on. my tip always remains exposed, but i want to fully cover it because otherwise, i dont think it would be as pleasurable during sex. any good tips on what i should do so that i can fully cover the tip of my penis with my foreskin once the condom is already on?