The previous method used Poses that weren't consistent on which direction up/down/etc were (the XY rotations could also get strange depending on what order you went in). I could have worked out a better setup on those, but it just seemed more intuitive to manually drag a target and place it where the base knuckle and end of each finger are located...the individual finger bones still use poses. I also isolated the hiding and unhiding of each finger so that it was less confusing and focus on only the right side, since it's unnecessary to see the left side unless you're double-checking that everything is the same (this rig assumes a CFA'd character).
The positioning of the thumb also positions the base of the carpals, so there is some rotating and scaling as well as the translating and that is also true of the index finger first knuckle...that positions some of the Hand Gizmo and roughs in the other finger bases. It makes it a little less "dummy-proof", but if I have the tutorial finished it shouldn't be a problem...I'm thinking.
Here's an example of a rough positioning of the thumb, index and middle fingers (I was in a hurry)...I was hoping to make it a quick clip, but I made it about ten minutes long, sorry for the length (and slop).
finger_placement_example_12_17_2010.mov