There is really nothing like fresh tomato sauce. I bought $16 worth of fresh tomatoes from the Farmer's Market and made two types of sauce, a fresh tomato basil sauce and a meat sauce from grass fed chopped beef.
The key to great sauce is keep it simple and use a food mill. This handy contraption I scored from who else but Nonna. Its kind of a pain to clean, but it makes perfect sauce.
The simplest tomato sauce can be just tomatoes and basil. You can add some onion and garlic, but thats where it should end. A little sugar is nice to sweeten it a bit and some peperoncino can give it a kick.
Here I just sauteed one onion and 2 cloves of garlic. Then I chopped the tomatoes and added them in with some salt and pepper. After letting them breakdown for a while on low heat to release all their juices, I ran them through the food mill. My mother believes that the food mill, by getting rid of the tomato skins, leaves the sauce sweet rather than bitter. I agree. The food mill has a few different size gratings, for thin to thicker sauce. I went thin on this sauce, which kept it summery and light. After you pass the tomatoes through the mill, you continue to reduce the sauce, now adding some more salt and pepper to taste and maybe some sugar.
When the sauce is finished, add fresh basil on top, which steams its flavor into the sauce. Basil does not need to be cooked along with the sauce.
To make the meat sauce, I browned the chopped meat in some lard with some fresh thyme. Then I added it to the passed sauce and cooked it on low heat for about a half an hour to get that meat flavor into the sauce. It was a really light and lean meat sauce, but again great for a summer pasta. At the end I added the basil. Everyone really seemed to enjoy it.