When I was a TD...I would figure out how many I had in each division and what holes those divisions would be on, and then I would literally throw the leaderboard cards down the stairs. Next I oudl go to the bottom and work my back up picking them up as I went. Then I'd go to the leaderboard and load them, whoever was on top went to the first spot for that division and fill it in that way.
I figured that as random as I could get. It still pisses me off when they seed the MPO pools at Worlds by rating because that isn't random at all.