I'm still struggling with, as a GM, turning a scenario idea or a goal of the PCs' into a proper adventure. A proper adventure has challenging, multiple steps — I'm failing to get the “multiple steps” part.
For example, if the initial idea/goal is “Rescue the people kidnapped from the tavern by Orcs”, all I can think of for how to turn this into activity in the game is “follow the Orcs' trail, then deal with them to get the hostages”, which isn't even two scenes of play!
This is a problem for me regardless of whether the goal/activity is generated by me or the players, and regardless of whether I'm pre-planning the session or improvising a situation during play.
This is a both a problem for me and for my players. We all find this unsatisfying.
What I've Tried
Creating Antagonists w / Goals
E.g., in the above example, “the Orcs don't want to keep the captives as slaves.” But that still doesn't create any events or other things for the players to do, besides still rescue them.
Creating steps for the Antagonists à la *World games' Fronts/Dangers
E.g., a step might be “Orcs kidnaps people and takes them back to lair”, but I've got nothing else to add as more steps.