The best thing to do to make an ankle sprain heal faster is to stay off it and don't put weight on the ankle. Minimal movement is key too. Slightly elevating your foot when sitting and resting wil make it less painful.
RICE ;
Rest ,try to keep off your leg
ice , a bag of frozen peas will do fine , 10 minutes or so
compression , a crepe bandage is ideal
elevation , lie on the floor or settee with your foot higher than your body
