Review your home’s layout; look carefully at how it’s rooms are planned out. You can use a tape measure and draw a diagram (or have your contractor do this!). Pay attention to awkward spaces that don’t work; these will be spaces that creativity and experience turn into useful square footage.
You may want to remodel all at once, or choose to do so one room at a time. Create a budget based on your time frame and your goals.
Build a scrapbook of magazine cutouts (or online printouts) of products and room layouts you like. This will help you set design goals and provide something you can show your remodeler.