Look at how the character feels when they realise what has happened. Do they feel alone, scared, confused? For the best story telling, pick something that would make them suffer the most (like the social butterflies becoming mute, the music club becoming death, art and photography club members going blind etc). This gives them more reason to undo the curse set on them.
Also think about who would set that curse and why they would do it. Are they jealous? Angry? Did they just want to see what the curse could do?
Think about what could cure the curse, or even if it can be cured. Does the person learn to live with their curse, or do they spend forever trying to undo it.
How do their friends/love interest react to the curse? Are they supportive? Does it frustrate them when they can't do anything to help?
