To counter the macaroni and spaghetti from boiling over you should put a wooden spatula in the pan. you can turn the heat to high, but it does not boil over anymore.
Adding olive oil or butter to cooked pasta is not necessary and also a waste of oil! Just let the last bit of cooking water sit in the pan, and it does not stick together!
To prevent your macaroni or spaghetti sticks together, you should rinse with cold water. This allows you rinse the starch off so that it no longer sticking together.