For me, the most important part of preparing a good bowl of paste is the sauce, either tomato sauce or white sauce. What you add to the sauce later is just a manner of taste, minced meat, seafood, veges or bacon. We used to cook the sauce with those ready mix stuffs. The worst are those in powder form with lots of artificial colorings and flavorings. Better are those from bottles, somehow fresh ones, like tomato sauce with cottage cheese or herbs. These are of course more expensive, a decent one will cost you around 2-3 Euros per bottle for 2 servings.
We try to keep away from these ready products and instead make the sauce ourself. Actually, it is very simple. The tomato sauce is somehow similar to the one we used earlier in making tomato soup or chili con carne, but a bit thicker (just use more tomatoes and less water). After cooking the tomatoes with garlic and onions for a while, just blend everything together in a mixer to form a smooth and thick paste. This is our simple recipe of making the sauce:
1 clove of garlic
5 big ripe juicy tomatoes
chicken stock (or just water if you don't have any), not too much or else the sauce will become watery
pepper and salt to taste
herbs (we used those combined herbs for pizza with everything)
one chili (up to you, we like it a bit spicy)
Among all different kinds of pastas, we like seafood pasta the most. Although we cook Bolognese the most since it is the simplest. We cooked today for dinner seafood pasta with schrimps, squids and salmons. Instead of using chicken stock or water for the sauce, we fried the shells and the heads of the prawns and boiled them to made kind of prawn soup. This method is very similar to the one of boiling the broth for "prawn mee". I always find it very wasteful throwing the heads and shells of the prawns away as the most aroma is found in here especially the heads. We fried the salmons, prawns separately and boiled the squids for a while before adding them into the sauce. This is a must as squids release lots of juices when cooking and it dilutes the sauce if put raw directly into it. Moreover, it will also cause the sauce to taste very fishy. At the end, just combine the seafoods and cooked pasta (we used the classical spaghetti) into the sauce and that's it. One should never overcooked the pasta, it should be Al-dente (firm but not hard). Else the pasta will taste very muchy.