Hello. I am trying to increase my flexiblity by doing side-splits (Chinese) and front splits (American) (not full spits). I also brace myself against a wall and swing my legs behind me and try to get them as high as possible. When I do my splits, however, I place 20 lb. weights beneath me, go as low as I can for a split (which is about a foot or more off of the ground) and lift the weights to help pull-push myself down. What I'm trying to say is, is this a good idea? If not, what are some other sugguestions for stretching (without machines or pulleys of some sort)?

Thank you in advance...

That's a bad idea. You don't increase you're flexibility by forcing the muscle to go beyond its natural length. You're in danger of pulling the muscles if you continue doing that. For my advice on how to stretch for splits, see this thread

I agree with the Shaolin Ninja,
forcing the muscles will only make the contract harder and fight you on flexibility.

Alright. I'll quit that. What are some of your (being anyone) sugguestions on stretches to achieve maximum flexibility and such? I do front splits and let my weight push myself down. Then I do the crotch stretch (as mentioned in the linked forum) and then a side split. I'll stretch for about 20 mins. but afterward (app. 30 mins.0) I'll be as tight as I was when I started stretching. Sugguestions?