My buddy swears by Nouvellechef's super soil recipe, you can lower the amounts to make smaller batches. He uses about 50% mix of this and normal soil, and when this is spent he uses it as the normal soil for mixing 50/50 in pots. Some plants may find that mix too strong but he said the majority liked it for him.
18cf organic soil or Pro mix or the like
2cf rice hulls
1tb per gal of medium or 12c, soybean meal
1tb per gal of medium or 12c, alfalfa meal
10lb's bone meal
18 cups Dolomite lime
4lb's epsom
6lb's rock phosphate
5lb's Azomite
1c humic acid
6lb's kelp meal
6lb's green sand
8lb's Bio-tone/Plant-tone