If you’re having trouble rolling the sock, try fitting it over a banana or another long object. Starting at the top, roll the sock down until it forms a donut shape, then slip it off the banana.
It’s handy to keep some water in an old spray bottle so you can evenly spritz your hair to dampen it. If you don’t have a spray bottle, use your fingers to flick some water onto your hair, then use a comb to distribute it evenly.
If your hair feels dry at this point, give the bun an extra spritz. Remember not to get it too wet, though, or it won’t dry during the night.