Natasha Betty Of ASILI GLAM shares her tricks of the trade (via Around The Way Curls):

Well, it’s all in the technique. These simple tips will help you in achieving bigger, more voluminous natural hair.

Step 1.
Do your regular twist out routine to stretch hair. My favorite as you all know is the flat twist method.

Step 2.
Ensure that hair is COMPLETELY dry before taking down twists. Drier hair equals more stretch and defined hair.

Step 3.
Blow dry roots by using the tension method for super stretched coils. The tension technique is quite simple if executed correctly. Grab your blow drier and attach the nozzle. Starting from the back of your head grab a medium size section of hair and blast low heat on just your roots while gently pulling hair away from head. This creates the tension the hair needs to stretch and gives the illusion of more hair!

Step 4.
Proceed to do this to entire head until complete. After blow drying roots, grab a wide tooth shower comb, flip hair upside down and gently comb through roots ONLY to add even more volume. Use the “picking” technique as if you had an afro. Do not disturb the entire curl pattern as you will end up with disheveled, frizzy hair. Only pick the root of your hair.

Step 5.
Flip hair back up and shake from side to side to allow curls to naturally fall in place. Hair will appear bigger, fluffier and 10 times more voluminous!

Results from using the outlined technique:

For Those Not Familiar With “Tension Drying Method” Look below

CN Says:
 I’ve used this technique with great success! I actually leaned on it pretty heavily when I was wash and going back in the day. But since my highly porous hair stays soaking up atmospheric moisture, shrinakge sets back in rather quickly and I’m back at square one. So I reserve this technique for fall/winter, low humidity days and special occasions.
 Another, non-heat way to stretch is to pineapple OR pull your hair into multiple loose pony tails or one low loose pony for a couple of hours (or overnight). Magic.