Freshly grate Parmigiano-Reggiano just before cooking rather than using pre-shredded cheese, which contains anti-caking agents that prevent smooth emulsification and create a grainy texture.

Save at least one cup of starchy pasta water before draining; this starch is essential for achieving a silky sauce consistency and helps the Parmesan incorporate smoothly without clumping.

Keep heat on low-to-medium while adding cream and cheese to prevent the sauce from breaking; high heat causes the fat and cheese to separate, resulting in an oily or curdled sauce.

Toss the hot, drained pasta with butter and a splash of pasta water off-heat for 30 seconds before adding the cream mixture; this prevents the pasta from cooling down the sauce and ensures even coating.

Slice garlic thin and cook it gently in butter over medium heat for just 2-3 minutes until fragrant but not brown, as burnt garlic creates bitter flavors that overpower the delicate cream sauce.