Do you just hit with your opponent for 5-7 minutes when you’re sent out to the court to play your match?
This is not how to do it. First, you should find someone (maybe your doubles partner) to warm you up maybe an hour or more before you’re scheduled to play. Second, use new or nearly new balls. After all, you’ll start with new balls for your match. It makes no sense to use old balls to warm up with just before you play with a can of new balls.
Next, start off hitting the ball back & forth gently so you can get your rhythm. This should be when you’re hitting your ground strokes. This is not the time to practice a particular side. Spend about 10 minutes doing this with the intent of hitting everything beyond the service line. Remember, a warm up is a cooperative endeavor. The more balls you keep in play, the quicker you’ll be ready. You should then go up to net & hit your volleys for about 5 minutes followed by some overheads for a couple minutes. Again, try to hit your volleys & your overheads back to your warm up partner. You should not be trying to put away your overheads. You’re still in cooperation mode. Your warm up partner should also hit some volleys & overheads so you can get your timing on returning these, as well.
Now it’s time to hit some serves. Start off just spinning them in, like an easy 2nd serve. Try to hit spots, not areas. Serving to “just get them in the box” does you no good. After 10 or 15 2nd serves, start hitting bigger serves, now that your arm has loosened up. Make sure to serve to both the deuce side & the ad side. I’d also serve into the sun, if it’s that time of day, so that once you start your match, you’ll know how to position yourself & your toss. You should serve for about 10 minutes. Your warm up partner will serve to you, as well. Once you feel you’ve served enough, play a couple games, one serving & one returning.
This should take about 35 to 45 minutes. Now go rest until you’re called to play your match. Then, when you warm up with your opponent for 5-7 minutes, you’ll be ready to play.