Good Afternoon, All:
One of the things I learned from Savage Worlds is the concept of the Plot Point Campaign. In essence, the Plot Point Campaign takes the concept of a central campaign-based story arc, and breaks it down into site-based (and somewhat partially time-based) adventure components. As each plot element is connected to a location, and players may explore the campaign setting at their own initiative, the characters can encounter these plot elements in whatever order they wish, and the pieces eventually fold together to point the party in the direction of the final scenes that mark the climax of the campaign.
The average Plot Point Campaign covers a range of nine to twelve core adventure scenarios that define the basis of the campaign itself. The first scenario is often the one used to introduce the campaign to the players, and the last two or so represent the culmination of the campaign's efforts. In addition to the core scenarios, many Plot Point Campaigns contain twenty to thirty unrelated scenarios that develop other aspects of the setting and even focus on smaller subplots that may last two or even three scenarios before being resolved.
In some ways, the Plot Point Campaign design is halfway between a story-oriented campaign and a sandbox style campaign. In the 1E AD&D Wilderness Survival Guide, IIRC, they call this a matrix-style campaign. Every adventure is silo'd based primarily by location, much like a sandbox campaign, but build to an overall story, much like a story-oriented campaign. The concept of setpieces, or small adventure scenarios and elements, really shines in such a setup, as the added emphasis placed by a larger-scale storyline adds to the usual sandbox experience. However, the story is not railroaded forwarded as many tend to experience with linear story-oriented campaigns.
Although there are a number of different formulas that one can come up with for a Plot Point Campaign, the best tend to resemble a diamond or a football when graphed out. You start from the initial scenario that introduces the hook for the adventure. This can be the group's first adventure, or perhaps the first one after they get used to one another. If they are interested, that adventure plants the seeds for the second scenario. In the second scenario, you typically present two to four elements that need to be accomplished before you can resolve the overarching issue. At least half of the elements that the PCs will need to accomplish will have a complication that requires them to undertake a second adventure scenario to complete. This brings us up to 5-8 adventure scenarios. Once the elements have been gathered, the final piece of the puzzle, which unites all the elements and/or reveals the final plan, must be undertaken as an adventure scenario. Then the Plot Point Campaign wraps up with its climactic one or two adventure scenarios, sometimes followed by a denoument.
It's a pretty interesting experience to try and write your own Plot Point Campaign, even if only as a guideline for a direction for your campaign should your players feel the need for such. Assuming ten adventure scenarios to make up the core path, as a GM you can intermix other non-related scenarios with that core path, such that you can assume you've got 19-20 different scenarios in the overall campaign, at a minimum. You should never assume that two adventure scenarios will be run right next to each other (except perhaps at the end), so whatever you create should be able to stand alone. If a particular adventure cannot stand on its own, then it's a smaller part of another scenario, and should be written that way. In this way, you can spend about half of your time (or less, even) on the core adventure, and the rest of your gaming time on smaller scenarios that build your characters, flesh out the world, create smaller subplots, and provide different adventuring opportunities as a change of pace.
As you collect your notes on these short adventure scenarios (which are rarely intended to run more than one or two sessions, if that), you will find that you are building up your world and filling your repertoire with information that can be used when improvising and running your game "on the fly". The adventure write-ups are portable, so you can adapt them to other campaigns in the future. The monsters and NPCs you'll create are even easier to recycle, and can be reused easily even in your current campaign. The same goes for new spells, unique magic items and other campaign elements that you develop along the way.
Ultimately, this approach lends itself well to one of the greatest pieces of GM advice on adventure prep I've read in a long time: always create your campaign elements with an eye towards recycling. Build it once, and you can then use it multiple times. That conserves your effort, and gives you more to work with as you move forward and grow as a GM.
Hope This Helps,