I don't measure anything...
I cut up two or three onions and begin cooking them in olive oil (I use bacon or sausage grease if I have it).
Once the onions begin to look tender and soft I throw in the garlic and a handful of basil leaves.
When the basil leaves have wilted I begin adding the tomatoes - skin and all and I add about a teaspoon of salt and a table spoon of black pepper corns. I let this simmer on medium low until it begins to thicken - stirring occasionally and crushing the tomatoes. (30 min - 40)
As it thickens I add about a 1/2 cup of homemade chicken broth and a second handful of basil leaves (though I usually cut these up). (another 10 minutes or so - consistency is up to you)
When the sauce is to the consistency we like I take it off the stove and let it cool.
We eat what we're going to for the evening and pour the remainder into mason jars and freeze for winter. (Remember anytime you freeze something in glass you have to make sure to leave room at the top of the jar for expansion while frozen or the glass will break)