OK -- this one is pure freestyle. The No-Handed 50/50 is popular freestyle trick, but it is hard to master. This is the move you often see pictures of (on the rare occasions you see a freestyle picture), in which the skater is balanced, standing with the board upside down, one foot standing on the bottom truck, and one foot under the board, holding it up. The name, I believe, evolved from the 50/50 Finger Flip, as did the trick.
I think that you should first learn the 50/50 Finger Flip. This will get you used to standing on the truck.
There's no getting around it. Balancing in a No-Handed 50/50 is hard, and takes a lot of practice. Just getting into one successfully takes practice.
There are many ways to come out of the No-Handed 50/50. I think this is a good way for beginners, since it allows you to return to a more familiar position (the 50/50 Finger Flip) to come out.
Obviously, it is more impressive if you balance in the No-Hand position longer. Once you get this down, you might try a 50/50 Wrap-Around to come out. Use your imagination.
In frame 2, I put my front foot under the board, preparing to scoop it into the move.
Now -- here is where things get weird.
In frame 3, I jump a little, and use my front foot to flip the board over. Look at the front foot. I'm already pointing it for the landing spot, right on top of the truck.
In frame 4, my foot is already on the truck. The board is still tipping over, but I'm using the other foot under the board to stop the motion by catching the board.
In frame 4, my foot is already on the truck. The board is still tipping over, but I'm using the other foot under the board to stop the motion by catching the board. Now the hard part -- balancing.
In frame 5, I've settled into the No-Handed 50/50.
A couple of tips...
1. I find it easier to hold the 50/50 if I keep the nose pretty high. If you let the nose dip down, it requires more effort to keep the thing going.
2. Once you get into this position, don't panic. Try to hold it for a few seconds.
In frame 6, I begin to reach down to grab the nose.
In frame 7, I've grabbed the nose and removed my foot, sucessfully transitioning into a 50/50 Finger Flip position.
Now it is time to come down. I hop up a bit, and use my hand to flip the board back over.
Finally, in frames 9 and 10, I just flip down, landing back in a Tail Stop position. You can also flip down to a normal, all-wheels-down position.
There are lots of possible variations. Try a 1 1/2 Finger Flip out. Or maybe a full Finger Flip to Casper...