Yes, I know how hard it is. I can do the splits on the floor, can even lift my hands up in air at same time, but when i'm upside down they just don't look like full splits!! You have to regularly practice and be consistant. I know loads of exercises to improve splits, on the ground and in the air. Partner stretching is always good as extra weight helps you, also bar workgives you something to push against. My favourite at the moment though is resting one foot, at the ankle in an aerial sling or hammock and pushing forwards (whilst holding the sling) until youre in a forward fold position.