When I had longer hair w/out so many layers, I used to do this for a temporary change, to go from very curly to strongly wavy:
Washed or cowashed my hair at night. Combed through extra LI conditioner and/or some gel. Created one or two loose braids.
(If the braid is too tight, it will take much longer to dry. Also, the tighter the braid, the tighter the resulting wave pattern. If too tight it creates an unnaturally strong crimp pattern rather than "beach waves" IMO)
I then gently squeezed the length of the braid to release some moisture.
I slept in the braid. The next day I gently unwound the braid and that was it.
If you're a violent sleeper, you could wrap your pillow in a towel first, then place it inside a satin pillow sheet ... or simply wear a hair bonnet, though that can slow down drying time some.