The soil improves permanently. Trees may never need fresh mulch, as in a few years the larger trees and shrubs become self mulching, the herbs hold their own, and only the annuals need annual attention. Potatoes are picked, not dug and the mulch kept up close to prevent greening off. They also do better in the second or subsequent years. Never bury sawdust or chips, just put them on top where atmospheric nitrogen breaks down the wood.
Worms add sufficient manure to supply the base manure.
Keep the mulch lose, don't let it mat, and thus mix lawn clippings or sawdust with stiff dry material like chips or pine needles, bark, etc. Observation and trial are the rules. Try a small area first, extend later. Now a little reflection will reveal the social benefits of a domestic sheet mulch. By using all organic wastes productively, you make the grade from consumer to producer, and the very nature of your garbage pail alters to harmless materials.