First, I'm talking glass bows...
I copied my beginning style from Louie Armbruster, who recommended "middle/middle"... center of riser on center of bow... Once you string it, before cutting a shelf, you measure the string to bow distance at the ends of the fades and the shorter measurement determines the lower limb. ( This was back when I used shelves, clearly a non-traditional development, first step toward compound bows
Also makes your bow unfriendly to lefties.)
Since I'm building glass and am short draw/low weight limit, I favor long fades, 18", to allow me to use longer limbs but still have a shorter working limb length.
Later, after reading much about shifting the riser for a shorter lower limb, I tried that, too. I've built maybe six bows that way and I can't really say I see much difference in the shooting. On my latest aluminum form, I marked one side for "middle/middle" and the other for shorter lower limb. I will probably go back to middle/middle. It just seems simpler and I like simple.