Two suggesions------------put electrical outlets at just above counter height. If you are going to have sewing equipment OFF the walls, be sure to put in some outlets hanging from the ceiling. I'm reluctant to suggest outlets in the floor. Murphy's law prevails and it would only be a matter of time until a pin or needle lands in a floor outlet.
If you don't want cords hanging down all the time, put them on a retracting wheel and just keep a lightweight chain or cord to pull the outlets down.
If you are going to have several pieces of electrical stuff, you might also think about a couple breakers. Be sure to leave room for a radio/boom box and TV maybe. AND A VERY comfy chair for your handiwork. I'd use a lot of the CFLs if you have then in Chili. And be sure they are placed to your best advantage. YOU will have to specify what you want-------------YOU know, THEY don't.