Other forms: burnished; burnishing; burnishes
That seductive gleam on that Porsche behind the dealer's window? It's called a burnish, a gloss only achieved by loads of polishing. Likewise, you can burnish a resume by polishing it until it's perfect.
A caution about usage: burnish in the physical sense is usually reserved for inanimate objects, not people — you usually wouldn't say that someone's appearance is "burnished to perfection" or that your freshly scrubbed face is burnished. But you could burnish a car, a suit of armor, or a copper kettle. Reputations are among the most common non-physical things to be burnished.