There’s an App for That!
There are several apps out there that can help you with power napping, or mindfulness and guided meditation training.
Pziz is a a pretty cool app for helping you take a nap. The app generates ambient soundscapes that are great for falling asleep. You also have the option of having a voice guide you to sleep, kind of like a guided meditation. You have a lot of options in configuring that voice. You can turn it off completely or you can actually have it fade out after a few minutes and just transition to that music.
There is a sleep timer function, so you can tell it you only want to nap for 20 minutes, and it’ll wake you up. That will help prevent you falling into those deeper stages of the sleep schedule and hitting that sleep inertia.