I've been setting thrust line/reference line on my fuses over the years by drawing the line from the effective thrust point (center of the prop hub) through the stab center. In other words, I place my stab CL on the reference line to make things easier, but plus or minus 1 inch makes no difference on a typically tailed pattern model, regardless. The fuse attitude is chosen when this technique is used. I prefer the fuse to fly neutral, neither tail high nor tail low. The stab is set at zero and typically I use fixed stabs, but not always. Temptress and Aesthesis have fixed stabs but Delta, my latest, has adjustable. The wing is set from the reference line

Years ago when we had all glass fuses, a sewing thread was stretched from the spinner center to the tail, inside the fuse, and the line was transferred to the fuse outside surface accordingly. This idea came from a guy who was as fine a builder as I have come across. As fuses became opaque, a laser line on the fuse outside surface works almost as well but not quite. The better method is to use a height gauge. I purchased a height gauge 25 years ago and it has served well in pattern set-up over the decades, along with a flat surface. The great thing about a height gauge is that once you have the fuse attitude fixed and fin vertical (height gauge establishes fin vertical) the stab and wing locations can be scribed on the fuse sides precisely within a mil or two. Of course, the thinnest pencil mark is around 10 mils thick and that's quite close enough for the precision we seek

BTW- I applaud Bryan's efforts to make this rather essoteric subject more undestandable to everyone. I don't recall anybody else stepping up to do a treatise of the subject as Bryan has done, although some folks have done a few things. He is passionate about the subject of perfect trim and I've had conversations with him about it over the years. We don't always agree on everything but do on most regarding trim.

Some, myself included, played with aft CG, as far aft as 40% MAC. I didn't like the model's severe tuck to belly and uncertain directionality. But other aspects of an aft CG were rather good. I arrived at more fore CG as a matter of developing what a model needed, the best compromise if you will. I don't set the CG at 25% MAC and forget it tho. For the TVC I design in, 30% MAC is more desirable. As Dave sez, there are several ways of doing things and another BTW, everything we do is a compromise