Gardening - My basic small footprint of a garden

We've fenced in a small portion of our yard to dedicate to what hopefully will be a very productive garden in the next few summers.  Initially the garden was all in ground planting and worked fairly well.  Now we are hoping to increase our yield many times over while not extending the footprint at all.

This area is about a 10' x 10' plot.  Lot of experimenting going on right now but by the end of the summer I hope to have it much more efficient and organized with a whole lot more actual square footage of plants.