Have another string/more strings to your bow
Definition 1 of 1
Pro Tip 1/3Metaphorical Origin
The phrase originates from archery, referring to having additional strings for a bow, as backup. 
By learning coding, she added another string to her bow, just as an archer carries extra strings.
Pro Tip 2/3Career Flexibility
Often used when discussing career skills, suggesting increased employability. 
John learned Spanish to have more strings to his bow in the business world.
Pro Tip 3/3Not Just Work
The phrase can also apply to social skills, hobbies, or personal development. 
She's funny and intelligent, with caring nature as another string to her bow.