Heat the olive oil in a large skillet over medium heat. Add the garlic and cook for 20 to 30 seconds. Add the tomatoes and sugar. Cook, smashing the tomatoes, until flavors develop and the sauce is thick and chunky, about 15 to 20 minutes. Stir in the basil and oregano and remove from heat.
TIP: For a quick marinara sauce that tastes like homemade, just stir oregano and basil into 1 1/4 cups store-bought tomato sauce.