I also have the frizzy, wavy hair problem. Too short for a pony tail though. I can clip it up on the sides with clips or bobby pins. I use a smoothing shampoo and conditioner by Joico. I've tried the John Frieda straightening products and they don't work for me.
In Disney, I don't fight it and I go curly. My suggestion is to invest in some good curl enhancing products. I am using Curl Life right now (it smells so good!). Don't dry your hair. Let it air dry. Just scrunch it from time to time until it's dry. I also "finger curl" my hair (that's the only way I can describe it! sorry!). Just wrap sections around my finger and it curls (with product in it!).
In Disney, I don't fight it and I go curly. My suggestion is to invest in some good curl enhancing products. I am using Curl Life right now (it smells so good!). Don't dry your hair. Let it air dry. Just scrunch it from time to time until it's dry. I also "finger curl" my hair (that's the only way I can describe it! sorry!). Just wrap sections around my finger and it curls (with product in it!).