The dock entrance is on a square face, with white lights at the four corners of that face. At the opposite end of the station, there's a square face with four red lights at the four corners.
Even if you're approaching from 'the side', you should still just be able to see red or white lights and head towards the white lights (or to the opposite end to the red lights, if you can't see the white). For me, this is the quickest method, as you don't need to wait to get within docking-clearance-range to find out which end is which.