Being able to kick, or lift your leg to the front, side, and back, enables you to move more freely and maybe eventually do the splits. You need a daily routine of stretches to become more flexible. You also need to understand a few principles of working safely.
Don't skip a warm up. If you haven't had a class or any other kind of exercise on a day where you decide to stretch, walk on the spot for at least five minutes, swinging and moving your arms freely. This will boost your metabolism and get your muscles a little warm.
For becoming more flexible to the front position, you need to engage your core muscles and lengthen the hamstring muscle(s) that run from your butt bone to the areas around your knee. There are two ways I recommend for this. If you are not able to lift or kick your leg to the front without the movement causing a change in the position of your hips, here's a great exercise. Stand in front of a chair. Lift one leg up and place it on the chair. Bend the standing leg, keeping your pelvis upright and your back straight. If you feel tension down the back of the leg on the chair, stop there. Very slowly lean forward, back still straight. You may only move a quarter of an inch, this doesn't matter. Don't let your back round. Hold this position for 15-30 seconds. That's your stretch. No bouncing or pulsing. Release up a little, then repeat. Change legs. As you get used to this you can do more repetitions on each leg. You want a stretchy feeling, but not pain.
You will feel a place where the muscles will let go a little, allowing more of a stretch. This is the "stretch reflex".
If you can already easily lift or kick the leg to over 90 degrees, or above your hip height, you can put your leg up on a ballet barre or counter top, keeping your hips facing to it. Maintaining a straight pelvis/back, lean over the leg slightly, while pressing the leg down. Hold 15-30 seconds. At some point you will feel the stretch reflex, maybe not on the first repetition. Do the same number of reps on each leg.
After a class or workout is an ideal time to stretch, but sometimes that's not possible. Always warm up for safe stretching.
With these ballet stretches, you will become more flexible for your ballet moves or cheer leading choreography.
Get more ballet warm up exercises, with the fast download The Ballet Bible.