• The 'dolphin glaze' from U-Pol works great because of how fine it is, and how easy it is to sand.  A lot of glazes get gummy, and this one doesn't (as much).
  • Glaze (or any filler) does not dry properly if it is put on in too thin of a film.  When using glaze, enough should be used just so it can be sanded down slightly.  This doesn't require a lot, but it's important everything dries correctly so it doesn't show up later on through the paint.
  • Glaze should be squeezed into pin holes in two different directions, otherwise the glaze tends to want to only stay in part of the pin hole.  They need to be completely filled.
  • Do not fill sand scratches with glaze.  They will show up throughs the paint!! Go through the sanding process properly, and actually sand everything.  
  • Don't abuse it.  Glaze isn't nearly as strong as filler.  It's meant to fill very minor things, like pin holes.  Don't use it as a body filler.  Also, it's best used over 120 grit or finer.