I always find my shot while in the complete upright position. Usually I can take my cue, hold it above the shot and "sight" the shot with the cue stick...I look for the angle that puts the OB in the pocket. I am extremely accurate with this process, it is when I forget to compensate for squirt and throw that it doesn't work. Really this works for me on just about any shot but a straight in one. But never had a problem seeing center ball, so straight in shots have never been a problem for me. The hardest thing to remember when using this method is to slightly overcut really long cut shots down the rail.
I am always amazed by how many people discuss pivots and other tricks to get to centerball...I see it as a symbiotic relationship between the balls and I line up accordingly. Granted, I don't make every shot and am no world beater. I should take a picture when I am at the local pool hall tomorrow so I can upload it, but probably won't remember to do so.