UFO is a somewhat advanced move. It is not complicated, but it is advanced because as a prerequisite you need a decent amount of strength. If you’ve been breaking for a while, trained a number of freezes, and have powermove experience, this will not be too bad. If you have just started breaking and you do not have previous experience in gymnastics or handbalancing, then this is going to be a lot more challenging.
Again, there are some good tutorials out there, so I will cover the most important points to troubleshoot the technique.
You do not need a clean planche, but it is helpful to be able to hold yourself up in some semblance of the planche position. Do pushups. Hold a handstand. Learn how to do an L-sit. Learn how to hold a tuck planche. Try to hold a straddle planche for as long as you can. Try handstand pushups. Practice transitioning between L-sit and handstand multiple times. Practice transitioning between L-sit and tuck planche. The possibilities are endless.
Learning a simpler move:
In this case, I learned how to perform "Buddha Spin", also known as "Gorilla Spin", as shown in the animated GIF to the right. You pull yourself from one arm to the other. You aim to place each hand after the other so that you can continue spinning before you fall down. I will explain this progression in an upcoming video version of this tutorial.
Once you are accustomed to performing the Buddha Spin, then you are ready to attempt UFOs. Make sure that you can perform Buddha Spins with straight arms, because that is what builds the strength required to perform UFO.
Tip #1: You must spin fast enough.
If you do not spin fast enough, then gravity will win, and your legs will reach the ground before the following hand can support you and keep you going. Observe the first clip below. I do not rotate quickly enough to keep my feet above the ground.
In that case, how do we build speed? The only key is practice. Observe the second clip. At this point, I am improving and getting more familiar with the UFO's movement, even though I still "tap". In other words, my toes and the sides of my feet are hitting the ground, so I wear comfortable sweatpants, jeans, or kneepads. That way, I can continue going even though I make contact with the ground.
Tip #2: Lean your body as far forwards as possible, but place your hands under your hips.
Physics dictates that if you do not lean forward enough, you will tip over. Note how in the demonstration below, my arms remain straight because I need to lean forwards while keeping my hands centered below my waist.
Tip #3: The more tucked in you are, the easier the move becomes.
The easiest UFOs are performed in a highly tucked position. It is harder to do with outstretched legs. The hardest variation is with legs straight and together.