If you scroll over your compass, you will notice your loc update real time. This is much easier than repeatedly hitting a /loc hotkey or typing in /loc.
The direction you would go depends on where you currently are. The idea, is to make your loc match thiers, obviously. If they are at -310, -362 and your at 300, 400.. then obviously you need to go the direction which reduces each loc. Notice, you can ignore the middle loc as it is height, and is generall not anything you can do about that. Anyhow, you can simply watch how your loc changes as you move, and pick the direction which reduces both.
The easiest way to find someone however, is to simply group with them and waypoint them. Very nice and convienent feature.