How do I improve my cheer jumps?

Ok so I just started cheer this year. I'm on the top team for my age but my jumps kinda suck! I dont have good height and my positions look bad. I don't suck too bad but they recently aren't what id call good. Got any great advice ingle to improve these? I'm talking all the jumps. Like the toe touch-herky-front hurdler-pike-and yeah..... Please HELP ME!!