Buy some velcro strips and put some on the top and bottom edge of a few towels you like for after a shower, where the fold over meets so it will stay. Pin it first then sew it on with needle and thread.
How to put on a towel around your chest when you get out of the shower? Every time I try it just falls off! (Girl situation..)
Pull it out behind you (hold up the top corners, the rest hangs down), then wrap one side across your chest (under your arm, over your breast). Wrap the other side around, and tuck the extra cloth into the front of the first side (which should be around the middle of your boobs lol).
It's probably falling off because the towel's too short, or you're not keeping the top over your chest.
I start by putting it around my back and pin it with my arms.
I just use a large plastic clothes pin