Kind of a dead thread but here goes anyway.
All the plugs in your garage should be on double circuits meaning the top plug is on a different circuit than the bottom plug. It's probably code in your area that the kitchen has to be wired that way. That way two high power draws on the same plug won't kick the breaker. And whatever you figure for plugs, add a few more per room. Every wall in every bedroom that a bed could be put against should have two plugs about 6' apart.
Think about making all single doors 3' wide, saves the knuckles moving stuff in and out of the rooms.
If you go with hardwood floors, the samples they will show you are all top quality grain matched and color matched. Expensive. If you can handle differences in grain and color you can find really good deals on solid hardwood. Some people hate the pre-finished mostly because the boards have beveled edges. It's a pain to keep clean.
Someone mentioned bathroom fans. Bathroom fans aren't for getting rid of stinkies, they are for getting rid of humidity. If the bathroom is on an outside wall, put a window in it.
If you are designing the house at all and you know where the house is being built and how it is oriented on the property, put some thought into cross ventilation. If you open the windows, is the wind going to blow through the entire house or just parts of it?
Two of your biggest expenses will be window/exterior doors and cabinets. Don't skimp on the windows. Personally I would stay away from the wood and metal clad. Too much maintenance down the road. Nothing wrong with vinyl. Sliders are the least expensive but casement and awning windows are better. Prevailing winds will help determine what type of window you put in which room. No matter what the salesperson says, the best windows out there will only give you an r-value of about 8 as a unit. Low-e is a must have.
Don't mess around with the old school stuffing insulation around the windows when they are installed, some contractors still do this. Use low expansion spray foam on all exterior wall openings.
Sorry kind of got carried away there. I spent many years helping people make all these types of decisions.
One more thing, the closet that are in the design, they're not enough. Just sayin'.
Oh, if you are going to act as the general contractor, good luck.
Have fun building the new house.