Arien described it well.
Over time you should develop pretty consistent warm-up patterns, i.e. take the same weight jumps on your way up. These will change somewhat over time as your lifts increase obviously, but the jumps will be pretty similar once you get past the beginner stage.
For example, if I'm going to do a heavy single front squat as the first exercise of my sessions, i'll do:
50 x 3 x 2
70 x 3
90 x 2
110 x 1
130 x 1
150 x 1
I recommend keeping the reps as low as possible and the jumps as big as possible - you want to get prepared, but you also want to incur as little fatigue as possible.
The consistency in your warm-up will come in handy for meets - you need to be able to plan your attempts, etc., and you want to be confident with those numbers instead of overthinking your warm-ups because you're not accustomed to the numbers or the jumps.