With pretty much any inlay, work it down to the best metal to wood fit you can get, then file the wood and metal together to get that ideal seamless smooth surface. Keep the inlay in place for most of the final wood sanding or scraping to avoid destroying the wood edges, but avoid excessive sanding over top of the metal lest you drag metal particles into the wood. Some very light sanding or scraping can be done with the inlay removed, but you risk rounding over edges.
Later you can remove the inlay for final polishing, using care to avoid rounding over any edges.
This method works best for me, though there are surely others.
Jeff