Use raised beds: Raised beds are a great choice for most gardeners. They're easier to maintain and can produce healthier plants and more bountiful harvests.
Don't disturb good soil: Overworking, compacting, double digging, tilling whatever you do once you develop a good healthy soil structure let it be! Seasonal composting and mulching should be all you need to do to maintain healthy fertile soil. Tilling, digging or any method of "turning" the soil will do more to destroy the environment you've worked all season to develop. The only time you should use a tiller or turn the soil is when developing a hard compacted usually clay like soil, for the first time. This soil type is pretty common in the deep south here in Georgia where I grow so people tend to till the garden at least once a year. Unfortunately doing so just perpetuates the poor soil quality and creates a hard "till pan" just below where the tines of the tiller can reach.
