If you ever want to put a rug in front of a door or lay tile at a later date you need to have your door thresh raised.  It can easily be done when you build by having your sill layed on a 3/4 inch of oak instead set right on the plywood floor.  Talking exterior doors her. 

May all your interior and exterior doors 36 inches instead of 32 or 28 inches.

Know where you want your TP hanger and towel hangers to go.  They do not come in 16 inch lenghts,  Notch out your studs out so you can apply a piece of ply wood in the studs (in the general area you think you want the racks).  Now you drywall of these areas and later when you want to hang you rack you have something, 3/4 plywood, to sink a screw or bolt into that will be strong.

You have your openings for your windows.   It looks like there would be plenty of room on each side of the opening to later hang your curtains.  Wrong.  By the time you trim the window you will have to (1) attach you hanger to the trim, which is ok I guess, (2) make a large hole in your dry wall to intall expandable hangers, not my favorite idea.  Here is what you do.  Simply cut some 12 inch long 2x4 or 2x6 stud pieces and add them to the sides of your framed area.  Now after the window trim is on you still have some wood in back of the drywall, right next to the trim, that you can sink a good screw into.  You will understand once you see the house framed.   

Make your rooms more square than rectanular if possible.  Why.  Once you put furniture along one wall or both walls your room is now a very narrow long rectangle.  Not something I like. 

Can you make your hallways 48 inches instead of 36?  Same with your stair ways.  Makes it much eacher when meeting people.  I had an uncle who was  built a nice big house with 36 inch stairways.  It was not a joy when he had people over.