There are several ways to accomplish a project like this without emptying your wallet. Easiest place to start.... bedding. Update those comforters! Comforters with a nice print seem to fare better and last longer than solids.
Next up.... paint, paint, paint. There is nothing like a fresh coat of paint to brighten things up. Play with color. A plain white paint is obviously easiest, but it also shows every scrape and scuff. Why not choose a color that conveys a beachy, vacation vibe, or one that is warm and inviting? Making your guest feel right at home.
Re-arrange the furniture. Probably the least expensive way to spruce up a home. Re-arranging the living area and maybe re-positioning some of the bedroom furniture is an easy way to bring new life to an otherwise stale space.
Letting your guests know that you put just as much consideration and pride into your investment property as your primary residence may help turn a first time guest into a repeat guest for your home.