Asking more questions is great advice, just stellar, and so is forming more NPC relationships. And don't be afraid to push the characters really hard, that's what the whole game is about! The PCs are tough as nails when it comes down to it, and if they go past 9:00 they can always take a debility instead of dying.
I found that I never really needed to consult the GM moves list for permission; I only really used it when I was at a total loss because it's good inspiration. As long as you're pushing your Fronts and making the world dangerous and real, trouble is going to find the PCs no mater what.When in doubt, look at your Fronts and just push something, like "oh, the market caravan just showed up but they've got nothing to sell, they're saying they were robbed in the wastes" or "you just realized that you haven't seen Little Timmy, and nobody else has, I guess he's gone missing?"
Because PCs are so tough and capable, oftentimes the worst thing you can do to them is hurt an NPC they care about, either off-screen or on-. Sure, the Gunlugger is nearly invincible, but that little kid he chats with in the marketplace? That kid is helpless. That's what I think it means to leave your bloody fingerprints.