The old expression "a first impression makes a lasting impression" is true here. The first thing a potential buyer will see of your home is the outside, so this is one area of your home that really needs to be looking its best. Ensure your lawn is freshly mowed, the sidewalk is free of debris, or snow, and your gardens are tended. Try to make your yard, and the entrance of your home as inviting as possible.
The inside of your home can be freshened up simply by opening a few windows. Letting in as much fresh air as possible will make your home feel and smell cleaner. Also remember to have curtains open as well as the lights on to make your living space as bright and as possible.
Just as important, spend some time cleaning every room, and closet. Your buyers will want to see everything in the house, so don't shove things in the closets at the last minute. The time and money you invest in preparing to sell your home will likely be returned in a quicker sale.