Analysis and Suggestions
In this entry, Kay has improved his 540 and wants more advice on how he can speed up his 540 and progress, thus to progress to more variations like Jacknives.
Well this foundation is already quite solid. Kay is clearly already using the whole dig and jump technique, which is required for a nice 540.
Other than generally practicing the trick to try to make it faster, one thing you can do to have a nice quick landing is to turn after your kick has crossed over. So, since you're kicking from right to left, once your foot is clear on your left said (or even right after it reaches it's peak if you want), wrap your arms in tight and try to look over at your target again.
This is essential for Jacknives, especially the wrapping of the arms. Wrapping your arms pulls your shoulders and tightens you up for a nice spin around, which is complimented by looking around at your target again. This should make you land with not only your face, but almost your entire body facing the target. This sets you up for a kick, you only need to practice these steps, then before you land, add a nice slicing hook on to the end. It will take timing to do this well. Thankfully, your non-kicking leg is already chambering in your regular 540, so that will help you throw out a quick hook when you Jacknife!
Wrapping is good! :) Have fun.