This whole hex-map project? Should have tried it years ago.
Building a campaign from the ground up. Start with the details, work my way out to the big picture. Rather than my usual strategy of starting it top-down because that seems like the logical thing to do, and then getting bored a few pages in and never going back to it ever again. Or, worse, never really getting started, because I can't think of the proper conceptual framework.
Well, no more. Now I'm doing my design at the encounter level. This requires interesting NPCs, who require secrets, which require clues on the map, which turn into more encounters, and suddenly I've got all kinds of crazy happening in this little map of maybe two days travel through a forest. I start out with "this town needs a leader" and I end up with "to the south are lots of elves, who don't like humans and have a serious green dragon problem."
This is fun.