It's *really* handy for starting off a story-line or when the player has no idea what to do next. I've seen it used a lot for things like "You know, [Faith-based-guy], you really feel like taking a walk today. Yeah, a walk down by the docks would be just perfect." and it just so happens that he runs into someone or witnesses a monster attack or whatever while walking down by the docks.
Another example - my character was getting home from an adventure and I didn't know that our enemy had rigged my apartment to blow up when I opened the door. Our faith-based character jumped in and asked the GM if he could use Guide My Hand to declare that I'd left my wallet behind or something like that. So, he shows up with my wallet just in the nick of time to pull me away from the blast and treat my wounds.
Then there's the "Substitute Conviction for any other roll" bit of Guide My Hand. For that, it's mostly a matter of reflavoring something that would normally take skill to instead happen by luck, coincidence, or divine intervention. I've seen it used for diffusing a bomb (sub for Craftsmanship, close your eyes, pray, and pull a wire), for a Contacts roll to find someone who knows about the current case ("You know, you haven't talked to your old friend James in a long time"), or for a Rapport roll to convince someone they need to shut up and help you right now (you're just so serene and convinced that they trust you instinctively).
