Step 1. Part your bangs into sections. Keep the side sections away from the main section of hair you are working on. You don't want them to get tangled in the area you are going to be teasing. Clip back the top layes of your bangs so you can smooth the unteased hair over the teased portion. This makes your bangs look smooth and less ratty.
Step 2. Hold up the bottom portion of your bangs straight up in the air. This will give you more volume when you begin to tease.
Step 3. Start teasing! Back comb your section of hair using your fine toothed teasing comb. Don't tease too much! You don't want a lot of nasty tangles! Lightly tease the fibers to the base of your bangs.
Step 4. Hairspray the base of your bangs, and lightly spritz the top of your section. You can use your hair dryer on a low setting to dry the hairspray faster. (I don't do this much with the bangs, just with the rest of the hair)
Step 5. Grab another section of hair leaving enough hair cliped back to comb and smooth over teased sections. Repeat steps 2 through 4 on your second section of hair.
Step 6. Lightly brush your top section over the teased sections of hair. It's alright if your teased sections get brushed out a little. Just don't brush the base of the teased section out too much, or you will lose your volume. Hairspray and mold how you want your bangs to look.
Repeat all these steps for whatever sections of bangs you have remaining. This will give your bangs a nice full and fluffy look; just like in anime!
Source: HezaChan.com