alt Hacker NewsSurprised no one here just does the outside border and spirals in (pinching off and immediately finishing irregular bulges). Looks neat, though more organic than rows, and is naturally motivating, as the second "half" always seems to go much quicker. Spiral the other way next time for evenness.
Tends to look strange, though spiraling around the edge twice before doing the usual lines will make your life easier, as you mentioned.