Most important thing is to not just make noise, but make each round count.
Unless your ammo is free, you are firing $ down range so make the best use of it.
Many of the training drills mentioned above can be practised at home with dry fire, and confirmed at the range.
Manipulating your guns and reloads, transitioning between guns, movement, trigger prep and sight picture while moving, draws etc can all be done for free (i.e. no ammo spent)
Things I practise (If I ever actually get to the range to do so) is utilizing recoil to drive me to the next target as aggressively as possible.
Basically transition speed target to target.
When done right, it should sound like you are just rapid firing with the same cadence between each shot, but in between shots you are driving the gun to the next target.
Also, depending on the match, getting into and out of awkward long range rifle positions, and making accurate shots at distance.
Not so much here in Ontario, but in the US, you will find you have to make long distance shots from a fallen tree, sand bags while lying downhill grade, rifle canted to the side etc.
Dry fire of these is one thing, actually practising the feel of recoil and managing breathing when you are crumpled up in a ball trying to get a stable firing position is another.
It will only be 5 or 6 targets in a stage, but will take the average guy up to a minute to get hits (or time out, whichever comes first) while the top shooters go one for one and destroy the competition.
Key point to remember, in competition, you don't have to be perfect.
Just have to suck less than everyone else.
Just saying that it's not gonna help get new people into 3 gun if they're afraid their stumbles are going on youtube. Not me though, I will be a rockstar.
