One of the annoying things about sweep bangs is that they have a mind of their own sometimes. I would recommend using a light mist of hair spray which will allow you to style your fringe and have it stay put. After brushing your hair, apply a light spritz of hairspray, and then quickly mold your bangs with your fingers. Spray a little more as needed to keep the hairs in place. Bumble & Bumble's Spray De Mode dries quickly and will make your hair soft to the touch.
I use spray wax to tame side bangs. This ultra light wax gives great hold but allows you to move your hair around to get it just right. It doesn't feel crunchy either. Plus you can use it on the ends to give your hair a piecy look. I use Goldwell Wild Unlimitor Spray wax that I get at my salon
Hope this helps!