I am glad this was brought up. I always warm up. Even before band practice I like to play a bit and then pack up my gear and go. Then the band always plays a warm up tune or two. I have gone without a warm up but I dont like it.
I at least run through a bunch of scales and fingering exercises and some chord progressions. I have no particular routine though.
On tour '76 - '81
Clean & Sober since '87