If you have trouble drilling precise hinge holes to mount hinges on doors because your drill bit wanders a tad (making doors hang kind of oddly), you need to know about the “Vix.” It’s a specialty bit made just for drilling hinge holes.
It has an outer cylinder tapered at the end that fits right into the countersunk hinge holes. With the hinge hardware in place, all you do is fire up your drill and press down.
The center bit is spring-loaded and lowers down, centered precisely in the hinge hole. It drills to a predetermined depth you set beforehand. It’s an invaluable specialty tool and inexpensive, to boot.