Pick your fresh tomatoes, slice in half and remove seeds.
Place tomatoes, flesh side down (skin side up) on a cookie sheet and roast in a 350 degree F oven for 5 minutes (or until skins start to pull away from the tomatoes).
Carefully remove skins and set them aside in a bowl.
Add tomatoes to a food processor or high-powered blender. Pulse quickly to liquefy contents.
Add tomato sauce to a heavy-bottomed pot and bring to a boil.
Reduce heat and continue simmering until tomato sauce is reduced down to desired thickness. (This will vary based on tomato variety.)
Meanwhile, prepare your jars, gather your lids, and either your water bath canner or your pressure canner.
To each jar, add one scoop of tomato sauce, then add 1 Tablespoon bottled lemon juice to each pint jar (or 2 Tablespoons lemon juice to each quart jar).
Add 1/4 teaspoon salt to each pint jar (or 1/2 teaspoon salt to each quart jar).
Add the optional 1/2 teaspoon dried basil to each pint jar (or 1 teaspoon dried basil to each quart jar).
Fill jars the rest of the way with tomato sauce leaving 1/2-inch headspace for water bath canning and 1-inch headspace for pressure canning.
Run a spatula around the jar circumference to remove air bubbles. Add more tomato sauce if needed to keep 1/2-inch or 1-inch headspace depending upon your method of canning.
With a damp clean cloth, wipe the rim of the jar clean. Place on lids and screw down the bands until resistance is met, then to fingertip tight.