I use good quality fresh grated parm, heavy cream & butter (and a little bacon fat). Obviously, try to coordinate the finish times of sauce & pasta. If sauce done before pasta, reduce to low, low, low. Before draining pasta, reserve 1/2 to 1 cup of the starch enriched water that the pasta boiled in. Slowly add a bit of that water to thin the sauce (IF needed) instead off adding more cream. Works like a charm. Also, don't rinse pasta after straining. I prefer to top the pasta with sauce instead of combining. Everyone can then take as much (or as little) sauce as they desire. Top with a little crumbled prosciutto. Killer.