Fredericka, I've been baking bread at home on and off for many years.
Weighing flour has made an enormous difference to the quality and
consistency of the finished product. As you suggest weighing flour from
each mill is the way to go. However you may want to consider going a bit
farther... use bakers percentages to convert your recipes from avoirdupois
to metric measurements. By measuring all your ingredients you will further
improve the quality and consistency of the finished product. And you can
substitute one brand of flour for another without worry.
Steven Leof