When you're doing a Hand Assisted Slide, you want to make sure you're going fast enough that you could actually scrub off some speed while you're doing your spin.
It's pretty much a 180 degree turn except you're going to use both hands in order to land this trick.
You're going to want to get down low, much like a Birt Slide. You're leaning forward. Again, you don't want to get over-extended or let your board get too far away from you.
It's very important that you keep your feet attached to the board, you keep your weight on the board as you do the trick.
You're going to push off the ground and let your back foot do the turning for you.
If you want, you can put both hands behind you and kick out to the front and let your back foot do the turning as well.
So it's really up to you. It's all about preference. Whatever you're more comfortable with.
If you want a little extra style points, you can just use one hand. You can use one hand in the front, one hand in the back. I generally like to use both.
Try and make sure as you're doing the trick, though, you don't let your hand slide on the ground too long, otherwise you'll get kind of a road rash on your hands and that will tend to hurt a lot.
So again, you want to get down low. You want to put all these maneuvers together in order to turn them into a trick.
And we'll call it the Hands Down Slide because it's really just a simple 180 degree turn except you're using your hands to assist you through the slide.