Since I have "the patience of a saint" (as my mother always told me ), I begin by zooming out to 5, find where I am on the map, drag my cursor up to (or down to) a corner, then go across, down (or up) one, and across again. Once in a great while I'll divide the map into two and work on one half at a time. I do have to admit however, I have once or twice completed about 3 to 5 columns on a side, completed 3 to 5 rows at the top, then the same for the columns on the opposite side, then I started at a bottom corner and row by row worked myself up the map. But, usually I just plug along row by row as in my first sentence. Guess I have "the patience."