Okay, first off your going to want to pour the tomatoes into a large bowl and crush them by hand.. removing the hard stem area and any bits of skin that may have been left on.
Mince the onion and give the garlic and basil a coarse chop.
Begin heating the olive oil on low and start sautéing the onion with a few sprinkles of salt for a few minutes until it begins to soften. Then, add in the garlic, red pepper, bay leaves, oregano, and fresh basil. Saute all of that for a couple more minutes but be careful not to brown or burn the garlic.
Add in the tomatoes and 1 teaspoon of sugar to start as well as a 1/2 teaspoon of salt.
Simmer this uncovered over low heat for 45 minutes to 1 hour... or until it reaches your desired thickness.
When it finished cooking your going to need to season it to your taste (I usually work in 1/2 teaspoon increments of sugar and 1/4 - 1/2 teaspoon increments on salt).
Remember, you can always add more but you cannot take it back out.
Also, for a thicker and richer sauce you can add a tablespoon or 2 of tomato paste.