I buy some store bought, because when it's on sale, heck, .88 for a big can is real cheap. I make my own and can it, too, but won't pass up the loss leader sales in the grocery store.

When I open a can of grocery store sauce, I dump in dehydrated onions, garlic, basil, oregano, fennel, olive oil, pepper (either red or black according to taste) and sometimes some powdered Parmesan. Heat it up and add cooked, seasoned meat or sausage if you want. It's really pretty easy to flavor it up.