For the first 3 years my heavy clay garden has been pretty much a failure.
The 1st year I cleared away the Juniper trees, dug beds while mixing in some pine needles and just a few branches.
2nd year, under the inspiration of "One Straw Revolution" I just planted as is, no new digging. Big failure, no harvest except pole beans.
3rd year, I planted cover crops for the winter and hoped again to give no-till a chance. Planted vegetables directly amongst cereal rye cover crops. Another big failure. The soil was too compact and without a good mulch the soil became hard. The drip irrigation only kept the soil wet about 3-4" away from each emitter, not enough for the plants.
4th year, success finally using hugelkultur.