When I began my GF/CF adventure, I would measure my GF flour the same way as traditional flour. I would use a spoon to scoop the flour into a measuring cup and level off the top with a knife. This method contributed to many failed recipes.
As you start to use GF flours and starches, it will quickly become apparent why the traditional method doesn't work. Not only is it extremely messy (the starches fly everywhere unless you are VERY gentle), it is very inaccurate. If you put the starch in the measuring cup by letting it sort of fall off the spoon and drop into the cup, you are actually packing down the starch. If you gently place it in the cup you won't pack it at all and may not have enough in the cup.
Please go and buy a kitchen scale. You will save more money in the long run by not having failed recipes. My scale was $2.99 at a thrift store. There are a ton of different scales out there, and you can find good prices on Amazon.com. Most scales will measure in Grams but make sure you check first. Grams are much more accurate than Ounces.
If you have a favorite recipe that you want to convert to GF, remember that 140g of my all purpose mix is equal to 1 cup of traditional flour. If you want to experiment with other flours and need to know their weight conversion, you can find a great chart here. I printed this chart and put it in the front of my cookbook for easy reference.
It won't take you long to get used to weighing your flour mix, I promise, once you get to used to it you won't want to go back to measuring cups!