I like the corners where the sidewalk to the front porch meets the street sidewalk, the sides of the front stairs, and between the porch and the driveway. Look for remnants of an old driveway, check to see if any breaks in the curb are signs of that or former sidewalks. Places where stumps were removed. You really should grid it out, but it is a good idea to try high percentage spots, incase you get interrupted...
Along the street is supposed to be the best because that is where the horses were parked, but I think all the sidewalk strips were clean out around here.