Well, process of elimination, and landmark recognition. Say there was a white blotch on the minimap near your home, look for it on the minimap. Combine it with usage of the Map Tool (Was this ever linked to you? If not, here
http://code.google.com/p/salem-map-tool/ ), and you should be able to find your way back.
The map tool itself would probably be enough to find your way home. Tip - the white 'selected' square in the map viewer pane is where you logged out or last were in that session. Also, every time you port, or enter a building/mine, it creates a new session - these are listed on the left.