"Curb appeal" is extremely important. That's the first glimpse your prospective buyers get of your home when they arrive. Go outside, stand back, and look objectively at the front of your house. If it's not as inviting as you'd like it to be, consider investing in shrubbery and annuals, perhaps a more appealing stone pathway, or a new rug on the porch. 
 

Paint helps. If you aren't able to repaint the whole house, at least update the trim or paint just the front.
 

Windows should sparkle and your front door should be oiled so that it swings smoothly. If you have a screen door, make sure that none of the screen is sagging or torn.
 

Inside, you want your home to be absolutely spotless so this is the time for heavy duty cleaning. If you can possibly afford to do so, hire a professional cleaning service. You can use your time to clean out all your cupboards and closets and eliminate any sign of clutter in your home. 
 

Keep furniture to a livable minimum, and store the rest in an accommodating friend's basement or garage for the duration. Less is almost always more when you are showing a house; when you remove furniture, rooms automatically look larger. Pack up as much bric-a-brac as you can bear to live without for awhile. 
 

Paint is the fastest and cheapest way to freshen up a room. Even if your kitchen is a little out of date, a couple of coats in current shades can do wonders. So will new knobs and drawer pulls for kitchen cabinets. Wallpaper is another story. Interior designers say that even brand new wallpaper is the first thing people change in a new home, so don't waste time, energy and money on it. The colors you choose should be neutral even if you don't care for them yourself. Such colors make it easier for potential buyers to visualize their own furniture in place and help them to think about the changes they'd like to make when they move in.
 

New vinyl flooring is fast and easy, and if you plan to add new carpeting, keep it's color neutral too. Don't invest in top of the line carpeting, your buyers are likely to change it again. 
 

New shower curtains, for every bathroom are a must because old streaky ones are a turn-off. If you can, buy a set of matching towels for each bath at the same time. Keep this new set just for show and put them away each time a prospective buyer leaves. Bathrooms are a selling point; make certain everything is shining.
 

When you are showing your house, pets should be out of the house. A lot of people are allergic so try to work something out with a friend or a veterinarian to hold your pets for a few hours when buyers are looking around. 
 

Even in the daytime, keep all the lights on - they make everything look nicer. Whatever the time of year, make sure the house is comfortably warm or cool.