I live on the side of a hill where springs outcrop across the top. The soil is clay with pebbles, in short an absolute nightmare. I bought a 3' square piece of galvanised chicken wire, the sort that is very study and has 3/4" square holes in. Then I made a frame out of 2x2 baton that fitted my wheelbarrow, and proceeded to cut the wire to size and then stapled it to the frame to make a giant sieve. Everytime I sort a border I stick the whole lot to a depth of a foot or so through the sieve. This is how bad my soil is, it's like 40% rock that is 1" or bigger. I then mix in a hefty load of manure in the bottom, then mix the sifted soil with spent compost from my toms or other pots. (You can just mix in normal compost but tis expensive for a big garden!.
If you have poor soil, realistically to get a good performance out of it, you need to put the effort in. My way is very hard work, but weeding/ planting etc is very easy, and I only have to mulch compost on top from now on. For my vegetables, I bought a load of second hand scaffold planks and made raised beds, then you can create the soil you wish.
Remember, clay soil is one of the best as it retains moisture brilliantly, if you get plenty of organic matter into it, and use a good mulch, you'll only be watering half as much as your neighbours.
