I thought I'd share a technique I've always used for getting the nut slots to be seated nicely, and it also helps to clean up a nut slot, eliminating ghost notes, and widening the slot enough for a Fender trem to work a lot better.
Take a 1 - 2 inch square piece of fine grit sandpaper. The 600 grit black/gray sandpaper works best. Take the little piece of sandpaper and put it under a string, folding it upwards, so you can grip it above the string. The paper will automatically bend itself around the bottom of your string. Slide it up toward the nut, and draw it through the nut, sliding it toward the tuners. Just like a file, it'll swipe out a little bit of nut material, cleaning up the slot. I do this on all strings, till all the slots are smooth. If you need to lower the nut slot a little, just do it a few times, and you can re-adjust the paper so you're always using fresh paper. If you perfect this technique, you can get the nuts dialed in on your guitars, so that regular trems work better, eliminating strings binding at the nut. It'll also fix strings that don't ring quite right.