I read in a study that a dynamic warmup compared to a static one contributes to a greater broad jump distance. So I would make sure that you're feeling nice and flexible before doing your broad jumps, especially when it comes to your hip mobility. From my experience, I jump farther when I can load the eccentric with a greater range of motion and swing my arms until they're directly over my head and pointing upwards. You can also try to hold your arms in the air as long as possible during your flight to delay the landing as much as possible. Legs be shoulder width apart, just make sure you're comfortable with your stance. I read that you have a tryout coming up so I thought I'd offer some advice in case they're testing broad. GL

Try isolating your hips, gett glutes/hip out and bend over spine straight until you feel a stretch in your hams and the angle between your spine and the ground is like 30 degrees or less. Then try jumping like that. Maybe you're squatting down instead of back and don't have strong hamstrings.

Also try evrything I said with a kettlebell, swinging it forward rather than up.