If you have a pit, grab a foam block.
Head over to the tumble track.
Start by doing 1 standing flip flop with the foam block between your ankles/legs. Focus on keeping that block where it is!
Eventually, do more than 1 flip-flop. 2, 3.. make sure you hold that block through them all. After a while, your body will figure it out
If you dont have a pit, you can make it really hard on yourself and put a piece of paper between your ankles.
Good luck!
Ryan