There is not typical size. It is dependent upon the architecture.

I'd recommend following Dark Sky lighting recommendations to avoid excessive lighting, contributing to light pollution, and annoying your future neighbors.

Just get it high enough its not in your eyes.

1/4 the height of the door

The above are perfect examples of lighting that doesn't follow dark sky guidelines. The lights on the first house needlessly illuminate the garage doors and columns adjacent to the front door, shine in the eyes of visitors, and shine in the windows of nearby houses. Path lights could have been installed along the driveway to guide visitors towards the door and downward facing lights could have been installed under the garage's eaves to complete a lighted pathway. The latter could have had sensors that turned them on only when somebody was walking towards or away from the house.