It depends on the day for us.
If a tournament is coming up, we do a little bit more cardio and rolling. Run around for 5 minutes, backwards, sideways, touching the knees, ankles, crossing the legs, etc.. Then we do 10-20 jumping jacks each, 10-20 situps each, and a few sets of pushups. After that, we stretch out for a good 5-10 minutes and just roll. No technique, just rolling. One of the black belt instructors does BRUTAL warm ups prior to big tournaments like the worlds and Pan-Ams. We do fireman carries, arm bars from guard for 5 minutes each while he walks around and tells you to hurry the hell up, triangles, omoplatas, and whatever else he thinks up. He will also have us drag each other across the mats holding onto each others gis with just our fingertips, leap frog each other, do the scarecrow, etc.. He is a maniac. I've seen quite a few people puke from his warmups. I almost puked once because we were pyramiding sprawls.. He'd have us do jumping jacks, then yell SPRAWL! We'd do one, then back to jumping jacks, then two, then three, etc.. he got up to 15, and I thought I was going to die. People were falling flat on their faces for the sprawls and cussing like sailors.
Normal days, we jog for about 5 minutes, do some front and back rolls, shrimp across the mats a few times, duck walk, crab walk, bear crawls, etc. It usually lasts about 10 minutes. We follow up with stretching, then work some technique and roll for the rest of the class.
I'm not a big fan of the brutal warm-ups because I work my cardio on my own time, usually right before class. Then he slams us with that. Oh well, I still love him as a coach with all of my heart.