I visited a farm in Kaneohe, HI about a year ago, and they showed me how they dealed with clay soil. I gave it a try and it seems to work.
They grew their vegetables in raised rows instead of flat ground. After tilling, they piled the soil into long rows that were about a couple feet tall and a couple feet wide. So it was like a raised bed garden without the walls. That way the soil stayed fluffy because you don't step on it. Also the mounds don't get saturated in water. The pathways between the rows were compacted clay, and you could walk on them easily. I tried this in my small vegetable garden, and it seems to work better for me than planting on flat ground. When it rained, I noticed water puddling around the base of the rows, but the rows themselves were out of the standing water. It's also easier to walk between the rows.
They also told me they mixed the Big R redwood shavings to make their soil less compacted, but I haven't tried that yet.