@candyquilt-- That's a good question.
Do you have a triangular bandage at home? You can use a triangular bandage to make a sling. Tie the bandage around your neck and put your arm into the bandage to keep it high. The point of elevation is to reduce blood flow to the area. The more blood flow to an area of injury, the greater the inflammation and swelling will be.
Sometimes, if the strain is not very serious, cold packs and the use of a splint may be enough. Just try not to move or bend your wrist because it can't heal if it moves.