What does your warm-up look like?

[octahedrite]

I hardly ever warm up, but in the interest of building good habits and taking better care of my joints, I'm thinking I should start! When I do bother to warm up, I usually do arm circles, some hamstring and hip stretches. Other days I do a few reps with the empty bar.

What about you? What does your warm-up look like?

(Mods, can we get a discussion tag?)