Source: Unearthed Arcana 73 - Feats

You have honed your proficiency with particular skills or tools, gaining the following benefits:

• Increase one ability score of your choice by 1, to a maximum of 20.

• You gain proficiency with one skill or tool of your choice.

• Choose one of your skill or tool proficiencies. Your proficiency bonus is doubled for any ability check you make that uses the chosen proficiency.