Once you've decided on what pasta you're going to eat you need to think about the sauce.
A jar of Dolmio or Lloyd Grossman does not constitute what I would call a pasta sauce. As I've mentioned previously in this blog, the time and effort it takes to make your own sauce really does make these silly little jars seem pretty pointless.
From my experience and research, there is no "correct" way to make a pasta sauce. The recipe for a particular sauce varies from region to region in Italy and indeed household to household. The thing that you need to think about when making a pasta sauce is what flavours are there and are they broadly speaking going to give you something that would pass as a "traditional" Italian sauce. For example, my bolognese is different to Antonio Carluccio's and his bolognese is different to Jamie Oliver's. Italians (and cooks like me who profess to know how to cook Italian food) argue constantly about what is and isn't correct.
However.... you can rely on the following three facts:
1. Not all sauces start with frying an onion. In fact, I have come across very few that do!
2. Italians usually only put one (or two maximum) herbs in their sauces. The idea of throwing basil, oregano, thyme, parsley, rosemary, bay etc etc all in the same pot is quite often why our English interpretations of Italian dishes fall flat. Get that packet of mixed herbs and throw it away! It serves no purpose whatsoever! Sauces are often flavoured with other things so it doesn't need drowning with a multitude of herbs.
3. Sauces are not overly thick and bunged on top of a pile of pasta. They are reasonably light and usually put "through" the pasta to coat it.
Follow these three rules, taste your sauces while you're making it (if it tastes delicious without adding another herb or spice, don't add it unless you know that it will taste even better!) and pasta sauces will become a doddle.