You can use any backflip setup for the layout. In this case we use a roundoff. As you see you have to take off completely straight and extended. No bend knees or arms during takeoff. Swing those arms up hard!
Back Layout
Performing tricker: bam.defocus
The Back Layout is a backflip without the tuck. You will try to spot the floor early to spot your landing. That means you will also need a little bit more height than for a backtuck (which can even be done very low).
In a layout you don't rely on the tuck to flip you over so you have to flip using your arms and your upper body. Try to get as much height as possible with your arms and lean back as you rise.
At this point you should already see the floor. This will make landing this trick a lot easier.
It's time to bring your legs to the ground again. Tense up your abs and drive them down. Keep spotting the floor.
Almost there.
Landing! Bend your knees to absorb the impact.
Tips
Drill your backtucks to get them as high and floaty as possible. The more airtime you have, the easier it will be to turn that into a layout.
If you are efficient with the concept of momentum blocking your can try to transform a run into a big roundoff that blocks all that momentum upwards.
Squeeze your butt and push out your hip throughout the flip! This will help with the flip rotation.