Experiment to find what works for you: an inexpensive anti-frizz serum may be adequate, or you might want to splurge on a more expensive curl-styling cream that moisturizes and adds definition. After washing, add a bit of product to wet hair and work through with a wide-tooth comb, working from the ends to the roots to prevent breakage. Make sure each curl gets a little of product from root to tip. When you're finished, use your fingers to scrunch the curls to give them extra definition. The healthiest way to dry curls is to let them dry on their own time. Don't wring out or rub your hair; this causes hair to become rough and frizzy. After you've applied the needed products, sit back and let your hair dry naturally. Avoid using a hair dryer unless it's a special occasion. The diffuser attachment spreads out the heat so that it doesn't flow in a direct stream on one part of your hair. Work your way around your head with the diffuser, using its prongs to lift and dry your curls around the scalp, down the back and sides, and down to the tips. Continue until your hair is slightly moist, rather than completely dry.  Set the diffuser to the highest heat and a low speed. If you'd rather have waves instead of tight curls, don't push your curls up with the diffuser; point it straight at them instead. Use a medium-hold spray to keep your look in place throughout the day, or add a drop of serum or wax to your curls to create definition. Only use a small amount to avoid weighing down your curls with product. Stay away from sprays that contain alcohol, as this dries out your hair. If you notice your curls starting to fall or frizz, wet your hair a bit and apply whatever product you like to use (curl cream, gel, mousse, or another product). Use your hands to scrunch your curls up, making them look as fresh as they did in the morning. Fill a bottle half with water and half with leave-in conditioner for a quick hair solution during the day.

Summary:
Use a curl-enhancing product. Let your hair air dry. Dry your curls with a diffuser if you're in a hurry. Finish with a touch of product for hold. Keep curls fresh throughout the day.