There is nothing I enjoy more than a good BLT! Especially in late summer when tomatoes are delicious and abundant.
Here in Lents, I am able to grow killer heirloom tomatoes. I buy plants at the PSU farmers market from my favorite vendor and generally get them into the ground late April or early May. I know that is too early for some, but I plant them anyway and cross my fingers. Any of the plants I can't find at the farmer's market I get at Portland Nursery.
I till my garden each year in the spring and add a few bags of composted cow manure, mushroom compost, chicken manure and a bale or two of sphagnum peat moss. There is no formula to what I buy, I just go to Freddies and buy some of each and then throw it all on top and till it into the soil. I also empty my personal compost pile and till that in as well at the same time.
I channel plant my tomatoes. Just make a long channel and plant the tomato on its side with just the top most part sticking out. All the planted stem will become roots. I add a little blood meal to the hole and mix in before I plant the tomato plant.
The best piece of advice I can give you is to invest in good tomato cages. I have galvanized steel square cages - they are $17-25 each but they can be used again year after year. They keep the plants upright and can support the weight without falling over. I have had too many huge plants fall over after a big rain in the summer.
Before you place the cage around the tomato, make a ring by removing the dirt around the plant. This makes it so that when you water you have a bit of a depression for the water to pool in instead of running all over the place. It makes it so much easier to water and know that the roots are actually getting the water they need.
I mulch around my plants with grass clippings from the yard. The grass eventually gets tilled in the next season.
I try not to water overhead during the summer and just water with the hose at the base of the plants.
I enjoy buckets of heirlooms every year using this process. I have more than I can ever use.