Drop those measuring cups
Learn to bake by weight and stop using measuring cups when baking. To help your baked goods, work and keep them accurate, you need to learn to bake by weight because every gluten-free flour has a different weight.
For example, if you run out of potato starch, you can replace it with tapioca flour if you weigh it. It will take time and probably some experimentation, but gluten-free bakers live by the scale.