Drills/Tips to explode up into serve?

[BirdWalkR]

Practiced some serves today and just felt awkward. I'm trying to learn to explode UPWARDS into the serve and i always feel like I'm either not going into the court enough or I'm just stiffening my arm and collapsing on the ball. I've tried looking online but I couldn't really find anything that pinpointed going up into the ball. Hate to keep spamming the tips/instruction section but I wasn't sure people would really respond if I put it in my other serve thread.

[5263]

My approach is to get the toss where it needs to be, then go up strongly for
a high contact pt that is within your ability to do thru a match.

[slowfox]

I used to warm up by throwing balls "up a mountain". Then I'd pick up my racquet and go at it. Serve practice was better. Works for me.

[LeeD]

Lower your trophy pose right hand. That allows you to finish your swing as you're hitting the ball, anything beyond is only to slow down and prep for the next shot.
Arch you body like a bow that is drawn, something some pros barely do.
After ball contact, your elbow and hand should be at head height or higher, while the racket is pointing straight down at the ground.
You have to slow down to preload your serves. THEN explode up and towards your opponent, around a 45 degree upward angle.
Watch Hewitt and Ferrero serves.