I have made my own stretching program which takes about 45 minutes to do...
I do it everyday.

Warmup: If i have time i run for a few minutes to get the blood going.
Then i start warming up my groin mussles.
Stand in a horse stance and go to side from side trying to keep your head at the same level. After sometime you can deepen the stance and/or move your feet out. Do this until you feel that it does not hurt when you move.(usually takes 1-3 minutes)

Stretching:
First i put up my legs in a 90 degrees angle
and start to move my legs down to the floor. It´s an ordinary split upsidedown. Lay there for 5 minutes, then rest for 1 minute and do it again for 3-5 minutes.
Now your groin mussles should be pritty loose. So now i do a little bit of PNF stretching. I do a stance that looks like you are sitting in the air with your legs in a 90 degree angle. Almost like a horse stance but in this stance you put your knees in front of you. Then put your elbows at your knees and start to press your knees against the elbows (20sec) then use the elbows to press your knees out (30sec) to do this as many times you can without standing up. Then i usually do another PNF stretch but it's to hard to explain how to do it.
So as a finish i put something slick under my feet and try to do a split stay down for 2 minutes (i know it hurts) and do it one more time. Oh yeah, i almost forgott you can do a bit of dynamic stretching as well...
just swing your leg right out to the side as far as you can 12 times.
After all stretches you should do some kicking. I start out with some slow roundhouses and sidekicks and then i do them quick and high.

and that's it folks!