Or even better in some cases: maps in your mind!
I've always been like a homing pigeon, when I get to a new, large city I often go for a long walk trying to do a circle, sometimes it works even without checking any maps!
Also I often run through a route using Googlag maps and streetview, that is almost as if I've been driving there once already.
But yeah, to be serious about an area and also prepared paper is the way to go!