STANDBY on tube amps - what's your practice

Was just wondering....I always let my SF Power Amp 1 warm up as well as cool down by using STANDBY button (about 10 min for each) and only then I turn on/off the main power switch. But if I take a 30 min or so break between listening sessions, I just leave everything as is...full power on....if I walk away for an hour or so - I always put the amp in standby mode.

What's your practice for tube amps?
How much you'd let your amp stay on (full power) vs on Standby?

Thanks!