If you follow package instructions for pre-preparation and portioning, you will end up with consistently overcooked pasta. I hate to so abrupt, but it turns out to be true too often. The instructions on the package are really for cook and serve immediately.
Pre-cooking is more art than science. If anything, set a timer 60 to 90 seconds short of package directions. Touching, biting and looking at the noodle is best technique; long thin shapes should just barely drop over edeges of tongs when lifted outof water. Thick shapes like penne or rigatoni or cavatappi should go to 60 seconds short of shortest cooking time on package. Again, touch and taste is best.
Drain and IMMEDIATELY shock in cold/ice water to stop cooking. Portion and chill. To serve, drop in boiling water for 30 to 45 seconds, and you should be spot on target. That refresh will even activate some new starches to adhere your sauce. Notice that I did not say anything about oil to prevent sticking anywhere. If your pasta gets to sticking when portioning, use a light mist of water to losen the starch and keep going.
I even freeze my noodles for up to two weeks with little to no degrade in quality. It is again more art than science and takes learning and caring a lot about the finished product.