Relying on recipes is fine, but the best cooks use measuring cups to train their eye. Fill the cup a quarter way with water. Memorize that visual. Now you can eyeball liquids in any glass or jug.
This is the same skill bartenders use. They know that a jigger holds 1.5 ounces, so they never need to measure twice. Your liquid measuring cup is the gateway to that confidence.
What Is Measuring Cups Used For at Michael Hammons blog
The Party Trick
Hosting a brunch? Use your measuring cup as a quick cocktail mixer. Fill it with ice, add juice and spirits, stir with the back of a spoon. The spout lets you strain directly into two glasses.
Bonus: you can scale up proportions by looking at the ounce markers. A Bloody Mary for a crowd? That’s 8 cups of tomato juice, 1 cup of vodka, and 2 tablespoons of Worcestershire. Your cup handles the math.