another string to your bow British English

 another string to your bow

Meaning: If you have another string to your bow, you have another way of making a living.

For example:

• Lots of people learn to teach English so they'll have another string to their bow.
  
• I've lost my job and I'll have to retrain for something else. I wish I already had another string to my bow.
  

Origin: Probably metaphorical, from the fact that if an archer has a spare string for their bow, they can still shoot an arrow even if their first string breaks.

Variety: This idiom is typically used in British English but may be used in other varieties of English too.