Ideally there will be about a millimeter of "extra" wallpaper folded over onto the frame
. This is caused by the thickness of the scraper and is the closest thing to perfect you'll get. Again, DO NOT remove the blade when making a cut! Hold the blade steady and reposition the scraper. And last, make sure you firmly press the wallpaper into corners. Loose, "curvy" corners are not cool. Keep your corners looking smart and sharp by "pushing" the wallpaper in towards it. Just don't push too hard as you may tear it. That's why I like to butter both wall and paper sometimes, as it allows you to do these kinds of things more easily.