There are a variety of ways to run games. Today I wanted to get some fellow GM opinions on Sandboxes, those games where the players aren't thrown onto a narrative golden brick road and led through the colorful landscape, but are instead dropped into said landscape and told to blaze their own trail.

So how does one ensure the best sandbox experiences? What tools are in your tool box and what levers do you add?

For myself, I've so far used the following:

1) A job thread, ensuring there are always at least three clear hooks they can pursue.
2) Multiple avenues to earn rewards.

Do any of the other GMs here have experience with running sandbox games? What did you feel was most successful about it? What parts do you think fell flat? What tricks did you use to keep things moving along without players getting lost or directionless?