for sure check tire psi and make sure your saddle bag is packed with the necessary items (co2 pump, spare tube, patch kit, etc.) I have done quite a bit of research about warming up and have concluded that a 5-10 minute ride in very low gear (target heart rate around 90-110 bpm). Then follow this with stretching mostly legs and then maybe lower back. By doing a quick warm up ride before hand, you will get the blood following and warm muscles allow for much better results from stretching.

After stretching get on the bike and ride the wheels off it!!