8-10reps is enough for a warm up imo. And keep it light. Just to wake up those nerves, joints, blood vessels and muscles up by letting them know something is about to go down.
I personally like burnouts. I fucking love the burn. Shit hurts so much! A great way to force the body to compensate and adapt. By pushing your mind past what your muscle thought it can do.
What are your goals? Stats?
Have you looked in to super sets and drop sets? I'd say to check out giant sets and triple drop sets too but you aren't ready for those. They not only force growth but improve your heart and lung strength and endurance.
If you want strong muscles, you need a strong heart too. Its a muscle too, duh
