I had a garden years ago in central Georgia.  Flat, exceedingly hot, heavy clay soil.  I did some good things with that garden.  I used compost, I mulched heavily, I grew my cukes on trellises.  I hoed dirt from my paths onto my planting rows to increase the effective depth of topsoil where my plants grew.

This spring, I'm going to try a few new things.  I'm going to try no-till techniques, double-digging, planting in beds rather than rows, and doing companion planting.  

No-till techniques are important because when you till the land, you destroy the structure of the earth.  While it's true that you fluff up the dirt, you destroy the little gooey stuff left behind by earthworms, and the teeny tiny roots that give the soil structure.  You also upset the micro-organisms living in the earth, moving them from the surface layer to several inches deep, and vice-versa.  Finally, you create a sort of hardpan about 8" below the surface, where the tines of the tiller compact the dirt.

Double-digging is back breaking work and it's time consuming.  The happy news is that you do it once, and you're done.  Basically you remove the sod, then dig a "trench" the width of your bed, about a foot in "length" (length being the length of your bed), and  about a foot deep.  You set that dirt aside.  Then you use a garden fork to aerate the bottom of your "trench" about another foot deeper.  Then you move back about a foot on your bed and begin a new trench the width of the bed, about a foot in "length" and a foot deep.  As you dig this second trench, you  use the dirt to fill in the first trench.  You aerate the bottom of the second trench with the garden fork, move back another foot, and keep on going until you reach the end of the bed.  When you're done you probably wont' need the soil you set aside... it can go into the compost or wherever you need it.  But, if you do need it, you can use it to fill in the last trench you dig.  Once you're done, you never walk on the bed.  You hoe it or rake it and lightly cultivate the top layers.  You add compost and mulch on the top, but your deep down work is done forever and ever.

Planting in beds rather than in rows is important because you don't waste as much land devoting it to paths.  The plants pollinate better in blocks than in rows, they shade the soil beneath them and so conserve moisture better and help prevent weed growth.

Companion planting is supposed to help cut down on diseases and pest damage because with the plants all mixed up, it's not as easy for a pest or disease to move in and go nuts destroying a portion of your garden.  Plus, some plants actually repel pests that affect other plants.  So, you'd want to plant these kinds of plants together.  And there are several types of flowers that attract pollinating bees while confusing or repelling pests.  Examples are marigolds and nasturtiums.