Here's the challengeYour character enters the scene in an emotional state that your audience will understand, showing who the character is or how they are feeling at the time?
Once you've figured that one out, try having something in the scene before the character enters. Let your audience see it before the character, and when he/she does arrive, show how they react to the thing in the middle of the room. It can be big thing or a small one, living or inanimate.
The ending to this scene is how will your character get around the "thing"? This is the assignment that you need to think about, storyboard some key poses and figure how a simple approach to this situation.
There are a lot of great examples of how to animate different walks in the Animator's Survival Kit by Richard Williams. Study his Key poses and breakdowns to apply those to your character. Here's a link to the book.
After getting this assignment, I usually see a group of people silently thinking about what to do next. Its a lot to take in at first, especially if you have never done something like this before. The best place to start is to think about a character in this situation and what is the "thing" that is blocking his path? The thing can be something small like a live mouse or a wallet full of money. How does the character react to this? This is how to character acts and reacts to it.
This scene doesn't have to have a joke at the end or a punchline. Just try to animate a character to show your audience a character personality they might know.
Wants it, Curious about it or doesn't want it all
Rough out some storyboard ideas to show the "thing" in the scene to set up the situation, the character enters showing us what type of person he is. Is he a sad begger, shuffling in or is he a proud upright wealthy person? Whatever the "thing" is, the character must either want it, find it interesting or doesn't want anything to do with it. This is in their reaction to the "thing" and you must let the audience see how they feel about it.
Students tend to fly by this part which is the heart of the scene. Instead, they do a wild take and then have the character jump over the object. They don't give enough time to the character's reaction which isn't just in the face, but the body is the driving force and the face is the secondary part. Watch this Flour sack animation, there is no face, but you know how he is reacting to different situations by his body language and attitude.
I often ask students to think about their scene more, perhaps even act it out themselves in front of a mirror or video camera. This saves a lot of drawing sometimes.
Here's a great amount of animated walks and runs from Disney's "Robin Hood". You want to turn down the sound to study the animation. But here you can see attitude's in motion during their walk or run.