Okay so my dd has hair that is super long (like down to her butt) so doing her hair for meets is always an issue. And, I must add that its not thin hair, its super thick hair that has a little bit of curl to it. Pony tails do not work and if I do a braid, the braid is also too long. So far, for her meets this year, I've done either cornrows (4 or 5 in the front) just to the crown of her head then I put it in a pony tail and put curlers in the pony tail. Or two french braids just to the crown with the pony and curlers. When I put the curlers in, we use the soft ones called "wrap snap and go." You can find them at Sally's Beauty Supply. You get like 15 in a package and this will suffice for my DD's hair. Usually we do this after my DD's bath so her hair is wet. It is important, especially with super thick hair, that it is somewhat dry when you do this, or else the hair is still wet in the morning and the curls do not work as well. Its is also very important to treat the curls with some kind of gel or super hold hair spray. Spray or gel each section of hair before rolling it up in the curlers.
When I take the hair out in the AM, she has pretty spiral curls in her hair and because even these are usually too long for her to compete with, I pin them to her head with bobby pins. So she has like a pretty pin-curl do that usually stays in for the whole meet. I also finish it with spray and send her with extra bobby pins in case one or two come out.