Learn how to adjust non-adjustable butt hinges here.
Fixed or loose pin?
In many cases the choice will depend on the style in which you’re working, but generally speaking, a loose-pin hinge makes it easier to fit large doors: You can remove the pin and take the door off for planing without the need to unscrew the hinge leaf from the cabinet.
When ordering hinges, take the width of the leaves into account along with the length. Otherwise you may find the leaves exceed the thickness of your door. It’s best to leave as much meat as possible at the back of the door stile, behind the hinge, to avoid break-out.
Brass or steel?
Many hinges are available with different metal plating, and sometimes with a variety of finish options such as antique brass or oiled bronze.
Technically speaking, a good butt hinge will have a pin that fits snugly between the leaves. Any sloppiness in this fit will complicate your job of getting a door to fit precisely in its opening.