Whipping half and half is a delicate dance. Because it has less fat, you must chill everything—bowl, beaters, and cream—to near-freezing. Fat molecules need cold to trap air bubbles effectively.
Add a pinch of salt to sharpen the flavor, and a teaspoon of vanilla for warmth. Do not overwhip. One moment you have soft, billowy folds, and the next you have lumpy, buttery sadness. Watch for the moment the cream leaves languid ribbons on the surface.
This instability is actually a feature, not a bug. It forces you to whip it fresh and use it immediately, which is exactly the kind of ritual our busy lives need more of.