There is an infinite amount of superstition and dogma about the appropriate place to stand at the oche. One of the present trends tends to be to stand with your heel dead center of the oche to aline your elbow, arm, and eye to the center of the board. Winmau sells a practice aid that advocates this with the belief that there is less distance to travel from side to side and that it is more consistent. I know when I was going through one of my many phil taylor phases that I would emulate this. Lately however, I have been using straighter barrels and emulating a more james wade/wez newton throw.
As we all have, I have been watching the pdc and bdo worlds pretty religiously and often in sticky darting situations the pros will move from side to side and throw from different points on the oche. Today I was practicing this, and surprisingly my accuracy has been a little better from the far edge. When I thought about it lots of pro's throw from the flanks.
Moral of this story. Never hurts to practice from different points on the oche either just to practice threading darts in tight places or just to challenge the status quo of your throw.