Hey! Listen up! I have a secret for you! Measuring gluten free products is no different than measuring gluten containing flours and products. I'm very serious; I would not kid you.
Seems that the gluten free community takes a great deal of pride in making something as simple as measuring dry ingredients complicated. I am going to show you through a series of pictures exactly how I measure all of my gluten free dry ingredients. As a side point . . . my kitchen is totally gluten free with all dedicated gluten free equipment.
1. Choose the correct size measuring cup.
3. Pour the liquid into the measuring cup to the desired level of measure. In the photo, I am measuring 3 1/2 cups of tomato juice for Tomato Aspic. Look at the measure on the left side of the cup. The tomato juice is level at the designated amount.
4. Get to eye level and make sure the amount measured is at the correct level when the liquid is still, aka, not moving or sloshing.
Note: If looking at the liquid in the measuring cup at any other angle will yield a very different result, as in an inferior product.