Any tips on how to play a perfect overhead clear, a smash and all while maintaining balance?
There's so much more basic stuff to learn like the split-step, handling of the grip etc. but you could do your research. Here's what I've always been taught.
Well the jump smash is one of the most difficult shots to play in-game so I'll talk about that last.
The 'overhead' clear refers to the opponent's clear passing into the deep court high into your backhand side. Overhead implies you have struggled but managed to successfully get around the clear. Now this is the difficult bit. You said overhead 'jump' shot and I highly doubt you should jump at all in a position like that. Position yourself behind the shuttle, non-racket foot forward and racket foot stepping in as you play it. I emphasise on putting yourself behind the shuttle because anything level with you is almost guaranteed to be a weak return.
If you're simply referring to a clear, ensure you're positioned correctly. You can jump for a clear, definitely, and especially if it's a fast one going deep and far into the court. Generally though you can simply sidestep/chasse for a clear as it tends to be high. Don't always feel the need to jump for a smash or clear. In that case you perform a scissor-kick, something also used in smashing/jump smashing. Without the scissor-kick you lose balance and this I believe is what you're after.
Scissor-kick mid-air during your jump smash or clear for three reasons:
1. Create momentum and perform a flat clear
2. Be in the correct position to move in for a potential drop shot
3. Regain balance. Without the scissor kick (or step forward, if you don't want to smash) you disregard your body weight and seeing as your racket foot hasn't moved forward you've got no momentum or power behind the shot nor balance.
So scissor kick.
Watch Viktor Axelson smashing. He isn't at his best at the moment but is a prime example of movement following/during a smash,
Hope this helped!