One decision you have to make is whether you are willing to use
synthetics or not.

On the suggestion of adding organic matter, I agree about adding organic
vegetable matter only if it's genuinely decomposed. Some folks have it
in their head that tilling in vegetable waste like kitchen scraps or
leaves is positive. Plants can't use rotting plants. The ingredients you
add have to be in elemental form.

For example, genuine (black) compost puts carbon back in the soil which
plants can use.

-SCR