So with your back foot, you want to kick the tail of your board down and right when it touches the ground you jump in the air off your back foot. This is the ‘pop’. It takes a little bit of getting used to but most beginners don’t really understand that initially, your back foot is doing most of the work. Then bring your knees up to your chest after the jump, the higher up you pull your knees the higher up your skateboard can go!
As you jump into the air, your front foot needs to roll slightly inward, and with the outside of your foot, you want to guide the skateboard as it flies into the air. Some people describe this as dragging the side of your front foot up the skateboard – that’s more or less what is happening, but what you are doing is using your shoe and the grip tape on the board to pull the skateboard higher into the air with you, and guiding the skateboard to where you want it.