To start I double dig when I can and let the frost break it up, add plenty of grit, home made compost, spent mushroom compost etc, I also add soil condition to mine and blood fish and bone, I try not to walk on it. Also any compost from pots/baskets (not the ericaceous though) get thrown on top, eventually you will get a less cloggy mess. But it takes time and effort the more you add the better it will get.