How do you keep a hairstyle the way it is?

My natural hair has a little bit of wave. I use a straightening shampoo and blow dry my hair with a paddle brush, put in straightening/heat protectant spray before i straighten it, and sometimes even hairspray a little after i'm done and still my hair does not stay straight. after about an hour the ends start to flit out quite a bit. even when i try to curl my hair the curls do not stay even with hairspray. any suggestions on what i can do to keep it straight or curled?