Eat ~100mg of caffeine really quickly (like a caffeine pill or slamming some coffee maybe) and immediately set a 20 min to 45 min timer and get into bed. Fall asleep and depending on your condition you will feel mildly to very refreshed after you wake up. You'll probably be up even before your timer goes off if it's on the longer side.
Hopefully this is helpful for some people but I've literally never been able to nap properly in my adult life. I'm rarely able to get to sleep outside of normal bedtime, and if I do, it's going to be for 2.5 - 3 hours. This wouldn't be as much of a problem if I was able to get myself to bed at a decent hour.
My only saving grace is that I'm out like a light when my head hits the pillow at 1 AM or whatever.