Start with good tomatoes, preferably meaty peeled romas.
You can take out the hard stem ends, but it's not necessary.
Sautee briefly some minced garlic in olive oil.
Add the tomatoes and more olive oil (about a quarter cup for a medium stockpot) and bring on medium heat to a low simmer. Salt lightly. Turn your light down. Add one eighth the amount of homemade tomato paste as whole tomatoes that you started with. If you only have canned tomato paste, you can drop this step.
Depending on the water content of the tomatoes, simmer for 1.5-2.5 hours.
When the taste of the sauce is just beginning to turn bitter and the flavors have been concentrated to their most delicious state, salt to taste and puree the sauce to desired consistency. Add more olive oil for a more rich, spoon-coating sauce.
Add Italian herbs or grated hard cheese as you wish.
Allow to cool and refrigerate overnight to further concentrate flavors.