Every encounter needs
1. A hook or motovation
2. A finish line or ending condition. Not necessarily the how. This is The dramatic question that the PCs need to answer.
3. A structure to know how to meet the condition.
4. One or more decision points
For combat this is all pretty easy. But for other types it is a bit harder to come up with.
You need to create decision points. The more decision points The more significant the encounter. One decision point and two to three dice rolls make a simple encounter.
For example, deciding to chase the bad guy or try to take a shortcut to intercept the bad guy is one choice. Chain a few together to make it interesting.
The decision on whether or not to pick a lock is not a decision point it is just an obstacle.
Example
Johnny Barbarian and Jimmy Bard need to free a damsel from the ogre at the bottom of the cave.
Dramatic question: can the PCs rescue the damsel before the ogre eats her tonight. The encounter will end if the woman is free.
Hook: The village chieftain will make the PCs official councilman if they can reduce his daughter from the Ogre. They start out at the mouth of the cave.
Decision Points: How do they go into the cave to rescue the princess? Of the PCs don't have any ideas then give some background.
There is dry hay going into the cave, it could catch fire but might also cook the captive.
The cave has some rubble over the opening that could be used for a cave in to trap them.
They could always just charge in
They can try and hire a guide to find a back entrance, but that might take more time.
All of test equal ONE question.
Structure
My favorite structure is simple but can be used over and over again. The five node mystery from the alexandrian.
http://thealexandrian.net/wordpress/37903/roleplaying-games/5-node-mystery
The basic idea is that you need to follow the three clue rule to make sure that any important piece of information is found and interpreted correctly by the PCs. By presenting three clues in each scene and pointing those scenes at each other, you can create a complete adventure.
