Soil and Mulch
The most important living element in the garden is the soil. It is not "dirt" which is what you collect in your dustbuster, and you certainly don't grow plants in it. Soil is full of living organisims and the healthier the soil the healthier the plants growing in it.
The use of organic mulch (wood chips, compost, etc.) is easiest and most natural way to keep soil healthy. Simply top your beds with 2" of mulch and replenish every couple of years or so as it breaks down. Mulch prevents water evaporation as well, and reducing the watering needs in our dry climate is always beneficial. It is also great for weed control as they are easy to pull, have a harder time getting established and many weeds actually prefer poor soil conditions.
Bark and wood chip mulch also ease fall clean-up labor. Just pick up what leaves you can and leave the rest to blend and decompose with the mulch.
Think of a forest ... things die and drop to the forest floor where they then decompose, feed the soil and the plants feed from the soil.
Pea gravel and small river rock can make aesthetically pleasing mulch. Big chunky rock or shale ... tend to be like paving the bed. If rock mulch is too deep it can over heat and suffocate the soil. Also, without a leaf blower and plenty of time, fall cleanup can be a nightmare.