Save a Little Pasta Water Before You Reach for the Colander
A small reserved amount gives you another way to adjust a sauce at the final moment.
The pasta is drained, the sauce looks too thick and the only cooking water left is disappearing down the sink. Reserving a little beforehand keeps an option open.
Finish the combination together
Serious Eats' pasta-saucing guide explains using cooking water while combining pasta and sauce. The water contains starch from the pasta and can help adjust the finished consistency. It is an ingredient to use deliberately, not a command to pour in the whole pot.

Editorial image from Blogdel's food collection, used for illustration.
For a simple home approach, reserve a cup, then add a small splash when tossing pasta with the sauce. Look at how the mixture coats the pasta. Add more only if the dish needs it, remembering that the water may also be salty.
Read the sauce you have
A thin sauce and a thick one need different adjustments. Some recipes rely on careful heat control, particularly when cheese or eggs are involved. Follow the method rather than assuming vigorous boiling improves everything.
The useful habit happens before draining. You save an adjustable amount and decide later whether it is needed. That is a good kitchen pattern more generally: preserve a harmless option until the dish tells you what the final step should be.

Editorial image from Blogdel's food collection, used for illustration.
Sources and further reading
References
- The right way to sauce pasta | Serious Eats · primary