When I prepare spaghetti for lunch I always try to find some time for my home made tomato sauce as well.
Somehow it tastes better to me than any other sauce I buy. I usually buy organic tomatoes or the home grown tomatoes of my neighbor; I chop them into small pieces and combine them with the leftover homemade ketchup. You can also add almost any store bought ketchup and when you mix them together you get a fine melted sauce with a few bigger pieces of soft and juicy tomatoes. You can opt for olive oil, sunflower oil , sesame oil or a different type of oil according to your taste. Add some salt and pepper, some oregano or summer savory and you will get an instant feel of authentic Italian cuisine.
Another reason I mix a can of tomatoes with a few fresh ones is because it is too early to get really good fresh tomatoes. Spring is the time that they are usually planted, so the ones you will now are grown in a glass house and do not have the full delicious taste and moisture.
When it comes to seasoning some people add mint but it is a little too strong for me. Oregano, savory and mint also improve and helps digestion and the smell is very inviting. This few ingredients will certainly complete your meal.