I custom built many of the doors for my townhouse remodel, and all of those required me to drill the proper openings for a lock set. This could be a complicated job, but it is made easy using a quick-set jig. The particular one that I have is over 20 years old and is sold under the Kwickset brand.

Kwickset installation kit.
Using the drill jig.
3/4″ auger bit.
Jig setup for latch bore hole.
Cross bore and latch bore.
Provided plug to mark corresponding hole in striker.
detail shot.
Here you can see the mark on the door jam.
Drilling the striker hole.
Using a template to mark the latch plate.
Job done!