The exterior creates the first impression but it's the inside that is the most important to most buyers. Try to make your home as appealing to as many types of people as possible.
For example a buyer can imagine white walls a different color but can be turned off by colors that are too bold.

Cleaning
-Clean everything in and out of sight.
-Shampoo rugs and wax floors. Wash or brush walls. Wash windows and clean blinds or draperies.
-Your home should be immaculate, beds made, floors cleaned or vacuumed, windows spotless, shelves dusted and trash taken out.
-Any repairs should be done, leaky faucets, missing tiles, broken screens, etc.
-Freshly clean all linens, draperies and shower curtains.
-If you are a smoker, clean any nicotine stained items thoroughly and refrain from smoking in the home during the period you have your home on the market.
-Clean the basement and garage.

Lighting
Lighting and space are two things that can make or break a home's appeal. When the house is being shown, turn on the lights when you leave, open all curtains and shutters to let in as much light as possible but screen out unappealing views.

Space
-Space is important, take a look around your home, take 50% of your closet contents and put them away.
-Take everything off the kitchen counters.
-Clean out your garage. Buyers want to envision themselves they are in clean and uncluttered open space.
-Weed out clutter in cabinets
-Create space by storing some of the extra furniture you've found useful (bureaus, bookcases, storage chests, oversized chairs) but which makes a crowded impression.
-Place the remaining furniture so that traffic can flow easily from room to room.
-Unless you're a skilled artist, scale down your personal art work (portraits, landscapes), posters,
signs, and family photos, especially in teenagers' rooms. Create a feeling of spaciousness.
-Keep normal walkways throughout the house clear so buyers don't have to walk around items in the way.

Kitchens
-Kitchen: stove, refrigerator, sink should be spotless and workspace clear.
-Clear counters, drawers and cabinets of unnecessary items.
-Put away all dishes. Don't leave dishes drying by the sink.
-Be conscious of odors caused by dampness, hampers, garbage and various foods.

Bathrooms
-Recaulk around tub if you can do it yourself properly if not have someone who can do it right.
-Clean tiles to sparkling shine.
-Clean soap dishes, mirrors, faucets and appliances (inside and out).
-Store cleaning supplies and hang freshly washed towels.

Bedrooms and Living Areas
-Keep living areas clean and inviting.
-Arrange furniture to allow a spacious atmosphere.
-Make beds, arrange couch cushions, dust shelves, vacuum carpets and touch-up walls with  paint as necessary.
-Wallpaper should be clean and adhere smoothly to the walls.
-Finishing touches such as flowers or candles add to the home's house warming appeal

Garage or Workshop
-Remove all cars for showings.
-Items should be neatly stored in shelving or wall units.
-Allow appropriate space for the home buyer to visualize their vehicle or workbench.
-Consider moving excess or over-sized items to mini-storage.
-Clean floor and if necessary repaint.