Step 1 Shampoo extensions like you would wash your own hair. Use gentle products and avoid cleansing or clarifying shampoos. Lay clip-on extensions flat to dry. Step 2 Use a soft bristle brush and comb tangles from extensions. Hold hair in place with one hand and brush starting from the bottom up. Step 3 Try to let hair dry naturally. Step 4 Protect hair when swimming in a pool and wear a cap. Put hair up in a pony tail when exercising to avoid tangling. Step 5 Tie hair up in a scarf when sleeping. Make sure hair is dry before going to bed to avoid tangles.