I also agree with sniff. I usually get my hair/bangs razored. So I'm pretty familiar with razor cuts. Though, unless you're good at cutting hair, you should go get it done professionally first, because you may razor/cut off too much, or at a weird angle. Using some light hair wax/pomade or something like this also helps the bangs stay in place and keep the shape cute. Lemme run into my bathroom to check on what I use....
Ok!

I use Aveda Control Paste (made with flax seeds?). It's great and a little goes a long ways. Other than the products I buy in Japan, this is the only product that I found that works well in the US.