Choose reasonable jumps all the way up so that you are not squatting something really close to your work weight. For example, if you are going to squat 275x5x3 for your work set today, 260x5 for your last warm-up is not a good choice as it could rob some of the energy you need to complete 275x5x3.
When you are pulling above 225 for your work set, start with 135x5.
Treat each rep like the work set in terms of focus and practice. Do not carelessly plow through them, but rather use them to refine your lift and utilize cues from your coach. And be sure to plan your jumps and reps so you have enough battery left for your work sets – the reps that make you stronger.