January 2014 update
For the past couple of weeks or so, I've been using a slightly modified blind structure.
Instead of the first two blinds being 20 minutes, they are now 15 minutes, making all of the blinds the same.
Traditionally, the later big blinds have always gone 1000, 2000, 4000, 6000, 8000, 10000, 20000. However, this can cause the final table to become a bit of a lottery, with some players forced all-in simply by drawing the big blind position when the dealer is chosen.
To make the slope a little gentler, the post-1000 big blind will now simply increase by 1000 each time.
I tried a bonus-chip system for a while to try to encourage players to register earlier and avoid a last minute bottle-kneck. This had some success, but wasn't ideal and put the TD in a postion of having to decide who gets a chip and who doesn't.
The blinds will now start at 8.45pm* whether we're ready or not. I'll aim to have the seat cards deal out by 8.40, so that players have a few minutes to find where they're sitting, go to the bar, etc.
I had some initiall concerns that the gentler blind increases might cause the tournament to drag. However, so far this hasn't happened, and so far tournaments have been finishing slightly earlier, even with 20 players.