How to 540 single leg

All you have to do is a doubleleg and then bring the second leg over the first:

https://www.youtube.com/watch?v=p3FrsnHYpPQ

"Do not"

Do not keep your knees together throughout the trick. You really want to kick the trailing leg over the first leg. When you kick over, it gives your hips a little "boost" to finish through quicker, resulting in a higher landing and a better aesthetic.

Do not bring your trailing leg over the second leg too early. If you kick over too early, it will really muck up the trick, and you will land low. This was actually my biggest problem with this move for a long time. You just have to be patient and wait until you are on your way down before splitting your legs and kicking over.

Do not forget to use your upper body. As you kick over, you can simultaneously coordinate your shoulders and arms to follow. It helps.

"Do"

Do it with your feet pointed. It doesn't take much to point your feet, it only takes awareness. This makes the trick (and all tricks) look infinitely better.

Do it with crayons in your mouth. A mouth full of crayons will not help you at all with this trick. What am I saying?

That's it

There is not much to say, and not much one can say with a mouth full of crayons. Huh? ... So if you have your double leg? Go get this trick next!