mom-6

My machine stays plugged in all the time. I turn the light on/off as needed. Some days it stays on most of the day, other times maybe only an hour or so.
I've had a bulb burn out (on a vintage machine) but it is easily replaced and not that hard to find.

applique

I have two industrial machines which stay on until I am finished, leave the house or go to bed. The lights are halogen and are turned off when I am not at the machine working for safety.

tessagin

I leave mine on until I know I am definitely done for the day. Sometimes DH goes in and uses it. He checks to see where the settings are before he changes them and then puts them back after he's done. I still check though because of changing anyway so no big deal. Caught him the other day cleaning it. Works for me. I also unplug when I'm done. A pia but we live in an old house with aluminum wiring.