Originally Posted by dlam
During warming up the groundies it's more for me to observe what type of strength my opponent has when they rally
You've already warmed up or should have long before any serious competitive match. The pros "warm-up" for an hour or two long before the so-called beginning of the match "warm-up". Stick with the traditional warm-up routine and things will go much better if you're playing against a real player--if you're not it really won't matter because he won't know any better either. If you need to "practice" or warm-up your shoulder, hit your serves on a practice court before your match. If it's a casual match, arrange with your opponent that you want to practice your serve for a while and maybe he can practice his returns.