What do you believe in? What are you trying to accomplish? Find solutions to 'wear down' an opponent, create momentary confusion, force turnovers, exhaust them, take advantage of weaker guards, turn defense into offense, and have a comeback game.
The "run and jump" defense is really a misnomer. We should call it "trap and switch," because it creates transient doubles with switching to deny or intercept passes.
Build the defense off one-on-one defensive attack. That has to be drilled. Young players often 'fear' getting beaten off the dribble. Too many play "dead man's defense" (six feet under the ball). Remind them with "nose on the chest", "head on the ball", "don't back down" or whatever your favorite.
What not to do? Attack with extreme pressure without fouling. First decision is whether you play full denial.
1) All off ball players must be 'ahead' of offensive player.
2) Trap horizontally not vertically. Mismatches will happen.
3) Build the defense off hyperaggressive one-on-one defense.
4) When beaten, run to a spot ("cornerback"/hip turn).
Layups will happen but can't dominate.
'Evolve' the defense playing "two-on-two." Have to build off sideline (trap from help side), middle attack, and back pass. Trap when dribbler loses vision or automatic middle.
Mechanics of trapping. I tell players "put the ball handler in a GLASS BOX." They cannot GUT PASS (through the trap), as the only passes out of the initial trap are lob or over the outside shoulder. The 'temporary trap' has the trappers inside feet at least touching if not crossed.
On the "back pass" a switch occurs (above).
Three-on-three (from inbounds). I prefer face guarding (hawk) with guy taking away 'over the top' pass.