How should I conduct an interview for a graduate software developer?

I have been "volunteered" to help interview graduates for an entry level software developer position. I have some scope to re-structure the interview and I am keen to hear any ideas that can help us find a good fit for our organisation.

So if you are a graduate, tell me what would help you shine in an interview?

If you are an experienced dev, what have you seen that helped to find good grads? If you have any advice based on bad experiences then I am keen to learn from those stories too!