Not really, other than to watch it for times when it'll crash because of a hickup in your internet connection. My solution for that was to write a simple perl script with a loop that automatically restarted it repeatedly each time it crashed. (The crashes are due to Python's flaky dns request function in the http module. So it has nothing to do with the script.) I usually had to restart it every 250,000 to 350,000 tiles. So if you're doing 2 million tiles, you might have to restart it 6-8 times to finish everything.

Also, the total build time is several days, so be patient while it finishes. I wish someone would invent threading to allow it to do more, faster, but alas, it's parallel only, so it's somewhat slow.