This is the Reider Decker Show from a few years ago going over how to do a strapless airs. The most important tip I did not mention in this video is there are two ways you can put the board into the wind when jumping. I go over this in more detail below!
Everyone has a natural tendency on which way to spin feels better. For me, it is easier to spin to the left. Riding left foot forwards I can do back rolls easier and when riding right foot forward I can do front rolls easier. For some people it is not easier to rotate the same way. An example is when they ride left foot forward they may like to spin left and when riding right foot forward they may like to spin right. Knowing which way is more comfortable for you to spin is helpful for just doing straight airs, as you have to drift one way or the other. Once you know which way is easier for you to spin, focus on locking your airs down that way then build your skills from there. Once you have your comfortable side down start practicing the other way that feels less natural. Below I break down doing a straight air in written steps. In this case I am pulling my knee up and drifting more as the start of a backroll.
Spot your kicker
Above we went over putting the nose of the board up and drifting on your straight air similar to the start of a backroll. Now lets go over pointing the board down and drifting similar to the start of a front roll.
Follow the previous steps until you get in the air.
Once in the air tuck your front shoulder in as you press on your back foot to bring the tail up and drift into the wind. Keep pressure on the board with your toes and the ball of your foot. It should feel like you are pulling the board up with your feet.
Drifting this way feels the best when you let go of your back hand. Keeping your front hand on is all you need to bring the kite back down when you are landing.
The higher you are able to bring the back of the board up while maintaining more pressure and control over the board the higher you can jump.
Before you have reached the peak of your jump sheet the bar out and start drifting downwind for your landing. ( see picture as I am fully sheeted out).
Strapless progression can move very slowly but once you start building on top of tricks you have learned it starts coming together!