I've always assumed that this is something inborn instead of learned -- hopefully, that assumption (which come to think of it I've never really questioned) is wrong -- but I have a very hard time orienting myself. When I'm walking up the stairwell in my apartment, I have no idea whether I am walking towards the road, away from the road, or perpendicular to it. I can sit down with a pencil and paper and draw it and figure it out by looking at it from a 'birds eye' perspective. But when I'm standing in a room with opaque walls and trying to imagine what room is on the other side, I just get really confused.

I found that frequently recording my voice and playing it back immediately afterward helps immensely. Up through the start of my junior year of highschool I did a very poor job with pronunciation in general and what I thought I sounded like, sounded nothing like what I did in fact sound like. I got a portable voice recorder midway through my junior year. I like poetry, so a few times a week I would spend a while (maybe a half hour) in the evenings reading poetry into the recorder and playing it back a stanza at a time. If I didn't like the way it sounded, I would repeat the stanza (or the particular line in that stanza that sounded wrong) until it started sounding right. Within a few months I very much liked the way my voice sounded, and instead of having people telling me I talked funny, I occasionally had people complimenting my enunciation. (As I side effect I also became able to read out loud which was something else I used to have a lot of trouble doing)