measure twice and cut once

• measure twice, cut once
• check twice and do once

measure twice and cut once

1. (carpentry, literally) One should double-check one's measurements for accuracy before cutting a piece of wood; otherwise it may be necessary to cut again, wasting time and material.
   • 1872, “Dressmaking”, in Hall's Journal of Health, volume 19, number 12, page 280:

     Look at Carpenters! . . . In old times it was a proverb "Measure twice, and cut once."

2. (figuratively, by extension) Plan and prepare in a careful, thorough manner before taking action.
   • 2008 November 9, Hilary Johnson, “Mergers rattle bank relations”, in Financial Week, retrieved 9 Nov. 2008:

     Mr. Paz noted that since the onset of the credit crisis, eBay, like other companies, hasn’t been able to "measure twice and cut once."