How To: Skill Specialization
The Specializations Setting Rule in Savage Worlds tends to get a bad rap¸ but if it's applied properly and carefully¸ I think you can get a lot of mileage out of the rule. How To: Skill Specialization aims to place a spotlight on when to use the rule¸ the best ways to implement it¸ and how it interacts with Edges such as Jack-of-All-Trades or rules such as Familiarization.
This requires a copy of Savage Worlds Adventure Edition to use.