Never. At least not in the sense of sitting down and doing musical exercises for the sole purpose of strengthening my technical proficiency.

But I do practice like a doctor, in that my work is my practice. I make music pretty much every day, and when I'm not playing or recording, then some process is actively going on in my head--always have some song being puzzled out as I go through normal life. Cannot escape it---it blares, tempts and cajoles.

I'm not against practice...I just don't practice it.