Here at The Kitchn, we endorse the practice of salting pasta cooking water until it 'tastes like seawater' which leads us to another important piece of kitchen wisdom: always under-salt your pasta sauce.
Most people agree that pasta should be cooked in very salty water. It's also common practice to save some of that water before draining the pasta so it can be used to adjust the consistency of the sauce as needed. The water, which is full of starch from cooking the pasta, will help to both loosen and add body to a pasta sauce.
What many people forget is that it the water is also salty, and the pasta itself is salty, too. So if you've already salted your sauce to perfection, you may end up with a too salty dish.
The method for using pasta water in your sauce is simple. Cook the pasta in salted water. Be sure to have your under-salted sauce hot and ready in a skillet on the stove. When the pasta is about one to two minutes away from being done, remove about one cup of water from the pot and reserve. Drain or lift the pasta from the water and add it to the sauce in the skillet. Finish cooking the pasta for a minute or two in the sauce, adding a splash or two of the reserved water as needed. Do a final taste test and add salt as needed. You may not have to add any!