A diffuser can be a very useful, but very confusing tool. The diffuser itself is a round attachment with holes spread around it and plastic tube-like teeth with holes at the end. What it does is dry curly hair and make it frizz free. Blow dryers can always damage your hair, but using a diffuser on a low temperature can create a nice, polished, yet effortless style. When I use a diffuser, here is what I do:
1: Start with damp hair, and apply a moisturizing serum. I prefer to use Paul Mitchell Super Skinny Serum. Just one pump on the ends really keeps the ends soft.
2: Apply a heat protectant spray, because you will be using heat and you will be damaging your hair. Chi 44 Iron Guard is definitely a favorite of mine, but if you can't afford it, Tresemme Heat Tamer Spray or Got2B Guardian Angel work just as well.
3: Once you have protected your hair, use a curl defining scrunching spray. NOT A SPRAY GEL! The absolute best one to use is the Regis Designline Curl Lock Scrunching Spray. This is a light spray with great results. Once you have sprayed all of your damp hair, scrunch the hair up from the tips. Hold the hair all scrunched together for 2-3 seconds, then keep scrunching.
4: Here is where you can use gel! Take a quarter-sized drop of hair gel, rub it in your hands to warm it up, then run part of it through your hair. Use the gel left on your hands to scrunch once again. This is now when you will want to part your hair the way you want it to dry. DO NOT GET GEL ON YOUR ROOTS! This will make your hair look excessively oily.
5: Now, on low blowing settings and warm heat (not hot!) hold the diffuser at the end of the hair so it is balancing, then move the blowdryer up so the hair scrunches slightly. The teeth on the diffuser should be touching your scalp, and you should slowly twist the diffuser back and forth as if to massage your head. Do this for about 10 seconds per section, then move to another. You may need to do some sections more than once, but not back to back! Keep doing this until your hair is 80% dry!