When I'm aiming at making large exhibition prints, I can use anywhere from 3-10 test strips for all different areas of the photograph to see how dodging and burning and adjusting contrast effects those areas and either making mental notes or writing them down so that when I do the print, I know upon first exposure all the areas to dodge and for how long exactly, then add additional exposures for the required burning and adjusting the contrast to the burn in a sequential order. In essence, using test strips effectively will increase the quality of your prints, give you a better ability to get really technical with the print and in the end, it will save you a ton of paper. Even if you're using 1/3 page test strips, it will give you a lot of visual information that is necessary for good print-making and still save paper in the end.