I have a warmup I call "The 20", it's great for lots of classes, I use it for Sculpt, Boot Camp, Personal Training & more!
20~Squats
20~Push ups (nice wide grip)/Push back to Child's Pose, then rise slowly
20~Alternating Lunges
20~Seconds of full Plank (x2, so actually 40 seconds)
20~Triceps push ups (tight narrow grip)
Push back to Child's Pose, then rise slowly and you are ready to stretch & go!
I love this as a warmup because it hits all the muscle groups, but you can even use it in a class, repeating "The 20" two or three times as a strength segment in a class! Enjoy!