Originally Posted by T-Mar

Setting a traditonal ball and cup bottom bracket is a matter of feel. Basically, you want just enough preload of the bearings so that there is no detectable play when you try to move the arms laterally. Most mechanics will adjust using 1/8 turn increments. If there's no play, back off progressively by 1/8 turn until there is play , then tighten 1/8 turn. If there is play, tighten in 1/8 turn increments, until there is no play. Once you get to this point, you may want to fine tune by doing smaller increments of turn. Make sure when you so this, that you tighten the locknut, as will reduce the preload.

One way to test whether the shell is properly faced, is to check the lateral play at different crank orientations. For instance, if the shell is not faced properly, you may get play with the crankarm at 3 o'clock but none at 6 o'clock.