I've used several methods
Over the years, I have used several methods, most of which have already been described.
I have used the laser bore sighters and the bore sighters with the grid on the end of the gun barrel.
After getting the bore sight correct, I go out and fire once or twice at 25 yards to be sure that I am "on the paper". Then I move out to 100 yds and fine tune the scope. Bore sighters are only good for "getting you on the paper" and final adjustments must be made after firing the rifle.
I always use the bench and sand bags to improve my stability when sighting in a rifle.