Player skills are based upon manufacturer and characteristic combinations. Skills are gained when you match skill books on any scratch card. Skill books appear about once per scratch card. A skill can gain up to 40% affecting the minimum score roll of a drink recipe. Skills affect manufacturer/characteristics and the AVERAGE skill of all the characteristics of the product is used. If for instance you have Goose Island Beer at 2%, Goose Island Ale at 1% and Pale Ale at 0%, the average would be 1%.
As of 6/14/2016, Kegmaster Cellar picks also give skills as if it was matched on a scratch card.
As of 6/17/2016 - It is possible to gain skills whenever you prepare a drink. The actual odds are 1:160 or about 0.625% chance per recipe. There is a graphical representation of the odds given when a drink is prepared. If this matches, you gain ALL skills related to products used in this recipe.