I've found that dipping a cup into the boiling salted pasta water for
reserve before draining is a good idea. The reserved water can come
handy.

sometimes pasta needs a little more moisture and the pasta water is
nice to have handy in case. When making plain pasta with basil,
tomato, parm, garlic, crushed red pepper, etc., I tend to add too much
olive oil, or cheese or maybe even butter so that it's not dry. By
saving the pasta water, it brings flavor together, adds moisture, and
makes it creamy without adding too much oil or grease. When having
spaghetti sauce, a little hot pasta water is sometimes needed to bring
it together.

Karen