Each character point you spend (1-3) allows you to learn say three different set bonuses.
Each character point you spend allows you to learn a new set bonus - it works the same as learning traits.
After looking at the new armor set bonuses (
http://forums.elderscrollsonline.com/discussion/118944/1-3-0-armor-and-weapon-sets/p1 ) it seems that all armor will have four different possible bonuses - two piece, three piece, four piece and five piece. This means there are four different things for the smith to learn.
Time to learn the set bonuses:
Two piece bonus = 4 days
Three piece bonus = 8 days
Four piece bonus = 16 days
Five piece bonus = 32 days
To be able to learn this bonus, the smith/tailor/wood crafter would need to get the original piece of armor and learn the bonus from it, destroying the piece of armor in the process. In other words, it would work exactly as learning traits does.
A benefit to this would be a large market would open up for the armor.
Special forges or materials to make the various sets could be required as well.
The crafter could then make sets of armor which are currently drop only IF they can obtain armor pieces to strip the set bonuses from.
Constructive criticism welcomed.