Minor ankle sprains can be treated at home by icing the ankle right away and using sports tape to safeguard for walking and sports activity. Use a special thin tape to protect the skin before applying sports tape---which can "latch" onto skin and cause minor skin irritation from its adhesive glue.
Cut a length from the 2-inch sports tape long enough to wrap from underneath the foot, just below the heel to come up and cross the top of the ankle bone to the inner shin.
Wrap the other end of the tape over the ankle bone to form an X, and wrap around the outer shin. Do this once more slightly above the X you have made.
Wrap a length of the 2-inch sports tape around the center of the foot to support the main, medial arch. If you have correctly taped your ankle and foot, you will feel a firm but comfortable "lifting action" from this "stirrup" you have created from the taping. If you feel discomfort or the tape is too restrictive, undo the tape and repeat until you find a comfortable fit. If you can, use the first layer of thin tape to buffer the skin. If you cannot find it in stores, just powder your feet with baby or foot powder.