Actually, luck has nothing to do with it: just good old sweat and tears.
One of my goals during the present building season was to achieve symmetry in a more consistent way. I even made molds for all five types of ukuleles I'm in the process of assembling now, but somehow, things always go awry at the stage of gluing the soundboard to the sides. At any rate, I was particularly discouraged with this, a new tenor shape: while I'm rather pleased with the contours, a silhouette shape I have been striving towards for a long time, the first one turned out skewed, and then the second one as well (I will still complete them, since I want to hear what they sound like). Finally, I devised a way of going through the process that seems to be working. At least, it did for this third attempt (the rightmost one).