Make sure you do some jumps or jog on the spot for a while to get your muscles warm and heart rate faster. This will allow you to stretch without injuring yourself.
Hamstrings
These exercises are only to be used when a dancer is warming up and the area of tightness is focused more on the hamstrings. At any time the dancer feels a lot of pain, they are to stop doing the exercise and seek assistance from Matt Forgie or another licensed athletic therapist.
Use a solid and stable object to rest your foot on. Make sure both feet are facing forward and your back is straight. Bend from the hips, not the lower or upper back.
Keeping your back straight, bend one knee in and have the other leg straight. Bend from your hips while keeping the back straight (so important!) and leg straight, and go only as far as you can to get a reasonable stretch.
With your back flat and spine aligned, start with both legs straight on the floor. Attach the strap to the ball of your foot and gradually raise your leg keeping it straight to feel a stretch. Only go as far as you can to feel a reasonable stretch.
Keeping your feet facing forward, separate your legs a decent amount. Bend from the hips keep your back straight until you feel a generous stretch. You can also turn your feet out and stretch as well, keeping in mind a flat back.
With your feet facing forward and shoulder width apart, bend from the hips keeping your back straight. Only go as far to feel a generous stretch. If needed, stretch near a chair or counter to place your hands so you are not tempted to arch your back.
There is definitely a difference when your muscles are warm and when they aren't. Be patient with yourself and go slowly while you are stretching.