Some best way to optimise is to read your data and work on them, Here are few things we did -

  1. Use Broad Keywords
  2. Cut out keywords regularly with high CpC
  3. Using negative keywords to cut out unrelated clicks and high cpc keywords
  4. Keep adding new keywords
  5. Optimize your Ad copy to get better CTR. Our Average CTR is 32%
  6. Work on page speed and content quality to get a Quality Score above 8 at least ours are 9/10
  7. Keep Decreasing Max CPC Everyday as your budget keep getting exhausted
  8. Run only on Mobile placement to get better results as currently 90% users are mobile users.