Lots of pasta left over? Don’t keep it in its sauce!
When making pasta at home, it’s best to serve it out onto the plates and then pour the sauce on top. If you’re sure you’re going to eat all the pasta you’ve cooked, you could mix it with the sauce before serving if you want, but if you find yourself with more pasta than you can eat, it won’t keep well if you’ve already mixed it with the sauce: the pasta will get soft, lose its texture and absorb almost all the sauce. So it’s much better to keep any leftover pasta and sauce separately.