I believe it was more of a mental thing than anything. The stretching was definately essential and I was getting closer but I had tried quite hard at the beginning of the session to get into the full lotus position with no luck.
It seems to be my left leg that I have trouble with (probably due to scholiosis) as it always seemed like I was putting too much pressure on my knee so I would then stop. I think that when I felt this I would probably tighten up to compensate. I may have possibly straightened my spine a little with good posture while meditating but when I actually lifted my leg up, there was no resistance whatsoever! It went up so easily that it really amazed me. Which is why when reading this thread it came back to me and I thought I would share the experience.
Coming back to your question though, when I reached down I just knew in my heart that I would be able to do it and I did. I had already done a lot of stretching through training and specificaly for this purpose at home and was quite flexible and to tell you the truth I was getting frustrated as I had seemed to stop progressing.
I have also found that while meditating for an hour in full lotus that I sometimes get quite sore near the end, but if I manage to take the focus away from the feeling in my legs it is much better and I sometimes go through a full session without any discomfort whatsoever. By taking all focus away I believe it allows me to fully relax my legs.
Another stretch to try in conjunction with the other great examples listed here is to sit as you would if you were cross legged but with the soles of your feet together. Hold the top of your feet and with back straight, apply downward pressure on your legs with your elbows, pushing your legs towards the ground. Hold it for a few seconds then bounce your legs up and down to loosen them a little and give a little relief. Repeat this a few times going lower each time. Make sure you warm up prior as this stretch is quite hard on your ligaments. You should be able to eventually push your knees all the way to the ground with enough practice.
Another good position though that anyone can do is to simply sit cross legged and place a pillow under each knee to hold the weight of each leg. My doctor recommended this one to me when I was starting out and it works great. Haven't seen it documented anywhere though.
Best wishes
