First, have a look at some past efforts here. Can you do better? It might be an idea to decide what you like about these ads and what you might improve.

Then, look at the adverts on THIS page and decide who they are targeted at.
Next, take a look at some of Apple's own, very iconic, ads. Massive cash prizes for spotting the spelling mistakes...

Also, checkout the instructions for using the GREEN SCREEN, here





















Finally, you need your own concept. Check these lines of appeal used by advertisers for inspiration...

2009 IPOD ADS