Master of the MojaveG 25

You can rely on online maps and your compass to discover as many locations as possible. Using online maps, you can do your best to mark the general area of a new location on your map with a custom marker. Once you reach that area, rely on your compass. Discovered locations will appear as solid upward-facing triangles, while undiscovered locations will appear as outlines of triangles. Simply face in the direction of an empty triangle and walk in that direction until you discover the location. Once you've discovered 100 locations or so, it might become difficult to compare your in-game map to an online map and pinpoint undiscovered locations. My best recommendation at that point is to pick areas of the map which seem to have many locations clustered tightly together, fast travel there, and walk in the direction of any empty triangles you see.