measure twice and cut once

saying2

1. •
   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.

   • Look at Carpenters! . . . In old times it was a proverb "Measure twice, and cut once." — 1872
2. •
   (figurative) Plan and prepare in a careful, thorough manner before taking action.

   • 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." — 2008