Small appliances should really be unplugged when not in use.
Not just for the small amount of savings of the electricity bill with small appliances that have a clock or other digital thing on them but also for safety reasons.
It's best to unplug small appliances such as your microwave, coffee maker, toaster, toaster oven, etc especially when away from the house.
If you're home it's okay to leave the small appliances plugged in but I unplug the small appliances when I got to bed or when I leave the house longer than a few hours.
It's just mainly for peace of mind.
If I go on vacation and stay longer than a few weeks from my home I also unplug my electric dryer as well.
I just don't want to risk something possibly chewing through the cord and causing a fire.