For consistent results, we always weigh flour. It’s very difficult to get consistent weights using a measuring cup. (We’ve tried by measuring series of ten cups and weighing each. As close as we can get is plus or minus ten percent.) So, we convert the flour called for in a recipe to ounces before beginning.
The following table can be used for converting cups of flour to ounces of flour so that you can weigh it with your scale. Different flours have different weights for the same volume.
Once you find a flour that works well for you (and a conversion ratio that works), stick with it. While there is some variation in flour from season to season (and from batch to batch), there is less variation than between brands.