Mulch, whether in the form of decaying leaves, bark, or compost, keeps soil healthy and moist and looks great doing it. Plus, chances are you can have the stuff delivered. The key to putting in mulch beds with pro appeal? Outline the shape you want with a garden hose, then dig up the earth inside the line and remove any weeds or crabgrass. Spread mulch in the tidy beds and be impressed at the results.