The best — and least expensive — way to improve your guitar’s appearance, as well as its tone, is to administer a thorough cleaning. But there are a few guidelines that need to be followed when tackling the dirt, grease, perspiration and smoke that may have accumulated on your guitar, either from regular use or neglect; otherwise you risk permanently damaging the quality and resonance of your instrument. Whether it’s an acoustic or an electric that you’re aiming to clean, these tips still apply. If you have a vintage guitar, you’ll need to take special considerations, as explained in a note below.