For wavy hair, I would suggest having your bangs cust so that the sides of the bangs on either side are a bit longer than the forhead. finger comb htem for the most natural look. You may want to use a bit of mousse for hold or for a straiger look briefly use a straight iron or curling iron.
Bangs are extremely frustrating. I wouldn't recommend them. They grow out very quickly and get greasy really fast. They also make your forehead break out in pimples. If you really want bangs I would recommend getting side bangs. At least these will not cover your entire face and are easier to maintain.
The best length of bangs for long wavy hair do would be about chin or cheek bone length. Cutting short bangs with wavy hair will cause the hair to curl up more once the weight has been cut off. You could always use a flat iron to smooth them out.
My hair is a past my shoulders and I have side bangs. I think those are the best for long hair. My hair is curly so i just run the straighter over them and they look cute and i reallly like them!
Try sweepy, longer bangs. Part them off to one side, so they cross over your forehead and sweep across your face. About to your cheekbone or just behind the ear.