Aw thank you!!!
Well, firstly, the best way to really strengthen your splits is to do lots and lots of oversplits. You can start out just with something small, like a book or a pillow:
And then slowly, over time, start increasing the height of your over splits and start using things like chairs and steps.
This will make sure you have really strong splits so your flexibility won’t be limiting you when trying to do splits standing. You can also stretch your lying down splits by using a band to pull your up like this
Work on getting your knee right up to your face.
You can also work on your flexibility for getting your splits while standing using a door frame or a wall like this
To be able to grab your foot and pull it to your head (heel stretch), you really just need to practice doing it over and over again. You can try grabbing your opposite foot (left foot with right hand) to get a stronger stretch too. I’ve posted some tips for the heel stretch on this page and here.
But, a huge part of doing your standing or lying down is strength not flexibility. The above stretches are important to make sure you have the flexibility, but you definitely will need to strengthen your muscles too.
For lying down splits, you can do leg lifts from lying down. Just lie on your back with your legs straight in front and raise your leg up to 90 degrees and hold it.
You can also do leg lifts for you standing up splits. How to do these depends on the type of standing split you want, do you want your leg to be in front of you, to the side, behind? Will you be in middle splits, front splits? It’s pretty easy to work out though, just lift your leg as you would to get into the position but do not go all the way (you are working on strength not flexibility remember!). You can then either work on reps (lifting your leg up and down as many times as you can) or on holding the leg in that position for as long as you can. I recommend you work on both.
I hope this helps you - good luck!