Best case scenario would be to get soil test but if you don't do that I would go to a GOOD nursery that sells bulk dirt in your area and describe or take a pot of your dirt and ask what people there do to amend. They will be familiar with your area.

Good suggestion above. Amend with organic material as much as possible. DON"T add sand. Is there a Living Earth place in your area. They sell bulk compost. In the meantime-- Mulch, Mulch, Mulch. The BtN is good stuff if worked into the soil at least a little, but as wantonamara suggested, see if you can find
a place to get bulk compost.

It depends on the type of soil you have. In DFW, we have that horrible black clay, which I removed. I replaced it with bagged soil mixed with manure and peat moss. So far, so good. I learned the hard way (of course) not to add more than one-third manure to the mix.

If you have clay, One can add gypsum, expanded shale and lots of compost. I have stick to your boots red death clay at my old house and in one small spot now. Decoposed granite is good only if added with lots of compost. Everytime I worked my land I add compost, if nothing else.

I read a thing where a person took a whole bunch decomposed hardwood mulch and mixed in the dirt and let it sit for a year to decompose further and had really good luck with that.