How would I go on about this? I'm purchasing an unfinished birdseye maple Telecaster neck from eBay, because it's hell of a lot cheaper than Warmoth. Is it ok to just cover the frets with the finish and just sand em down later with some steel wool, or should I cover the frets with tape?
You can spray the whole thing with lacquer. The frets are not going to absorb the finish like the wood will so you can just scrape it off or even just play the guitar and let it come off on it's own.