Related Clues:

• Go for the gold?
• Give an edge
• Improve, as skills
• Use a whetstone
• Small silvery fish
• Add to or subtract from
• Change a bill, say
• Pinch sharply
• Perfect, as a skill
• Make changes to
• Got a whiff of, old-style
• Process, as ore
• Refine, as ore
• Get the lead out?
• Change a bill