Use fresh lemons for best flavor and watch the pasta carefully as angel hair cooks quickly. Reserve pasta water to adjust sauce consistency. Grate parmesan fresh for better melt. For lighter sauce, substitute half of the cream with milk. Variations include adding protein like grilled chicken or shrimp, vegetables such as asparagus or peas, or swapping herbs and cheeses. Vegan versions can use plant-based butter, coconut or cashew cream, and nutritional yeast.