Learning a new technique requires lots of trial and error. If you’re acquiring a new skill or experimenting with a new design don’t use your sterling silver or gold-filled supplies! Instead keep a stash of lower cost metal supplies, like wire and sheet metal, to you get through your learning curve without breaking the bank.
When I was learning metal stamping it took many, many tries to figure out how hard to hit a stamp and how to angle my hammer to get the best impressions. I practiced stamping on less expensive, copper sheet metal until I was comfortable enough to move on to sterling silver. If you’re learning to make simple loops or to wire wrap try practicing with base metal head pins or a craft wire!