for hand sanitizer! LEGOs suspended in a liquid soap dispenser. Fun to put out at a LEGO party or everyday use in your kids' bathroom! I'd probably search for a cuter dispenser, maybe more geometrical, but still such a cute idea!
Hair Appliance holsters: Use hook-and-loop tape to attach lengths of diameter PVC pipe to the vanity door to hold the curling irons. Do the same thing with pieces of pipe to hold the cords. Let your curling irons cool before you stow them away.
simple sewing DIY to help shirts that slide off your shoulders! Sew snap into inside hem of shirt and clasp it around your bra strap. Also helpful for bra straps that always seem to fall down even when tightened.