For finish carpenters, fine-tuning the fit of a new interior door offers plenty of bang for the buck. There’s a lot of easy gratification for little effort. The final fit mostly involves door-hinge adjustment after the painters have finished.
First, I check that the door is swinging properly on its hinges. If the hinge leaf fastened to the door is not set fully in the mortise because of paint, plaster, tape, or misalignment, the hinges will bind. This might cause the door to creak or to spring back from a closed position. If the mortise in the jamb is set too close to the stop or if the leaf on the door is not set far enough across the width, the door will bind against the stop. If this is the case, you will probably see telltale signs of scraped paint on the door where it rubs.
When adjusting hinges, I often have to adjust the location of screw holes. Rather than struggle with a hole in the wrong spot, I simply tap in a plug and drill the hole where I want it.
After I get the door swinging properly, I adjust the hinges so that there is a consistent gap between the door and the jamb. When making corrections to the gap or any adjustments to the door, I make incremental changes. Often, going forward by small degrees is easier than going back by any amount.