From the kick off, I always position myself on the left hand side in the half of the team taking the kick (in line with, or just back towards the goal, the rear of the centre circle)
Not a part of the field you would normally frequent on your diagonal, but the thinking behind it is is that the team taking the kick will probably be moving forward, so you also move forward and as you cross the half way line and move into the other half you are now in the right place on your diagonal.
HTH
Jeff
That's the advice in the LOTG 'practical advice' section. Picture has the referee on the left of the team kicking off. I've been trying to do that more myself recently.