We live where its rather sandy so I have to amend, amend, amend. I use compost made from my chickens' and rabbits' waste along with leaves and grass and whatever. Though I don't double dig (I think its a waste of time unless you're going with potatoes or looooon carrots) I add compost to soil about one spade down then add more as a top dressing throughout the season. After two seasons, its looking better and worms are finally everywhere. Now if I can just get the chickens to leave the worms alone and just eat the pill bugs and slugs. I'm considering raised bedding next year, just cause it looks so neat and the water can get way down.