I did a post like this a while back and got some great ideas, some of my favorites are.
-Washer Dryer in garage (makes clean up quick)
-Do an Ice Maker
-Electric water heater efficient in space and power
-Big ass fan & Evap cooler works wonders
-Compressor on a switch
Next shop I build I would do different:
-Wont do a shower, I never use it.
-Have the concrete contractor dye the mud a dark gray, then use sealer and densifier. Much cheaper than epoxy and looks nice.
-No windows on the West wall, its hot and the window coverings were expensive because of the odd size
-Install big CFM exhaust fans on a timer to suck out heat when you want to cool it down. Save money on cooling and speed up the time to cool
-always make it bigger, always.