At one time I had plugged my iron into an extension cord for convenience. Unfortunately, the iron would work intermittently. I thought something had to be wrong with the iron.. nope - it was pulling too much power through the cord and would just shut off.
Now I just plug it into the wall directly.
One good/bad thing about my sewing room is that as a house built in 1969, the former-formal-living-room-now-sewing-room had NO light fixtures wired into the ceiling.
All of the power outlets are controlled by the light switch.
My DH installed lighting for me.. and when I leave the room I turn off the lights and EVERYTHING is off!