TOEFL® writing section: Very structured text? Rather base it on experience?

[Atlanticcity]

Hello everybody,

I'm taking the test on Saturday - of course I am preparing all the time - and I'm nervous.

Here comes my question: Would you experienced people suggest that I do what my teacher told me: Write a very and obviously structured text (introduction, body paragraphs, summary) - based on theory.
OR: Shall I rather write a (of course structured) text where I bring in an experience I've made; The model answers on the Kaplan CD are all rather short, less structured and based on what the writer experienced...
So I'm pretty confused! What would you recommend me?

Last but not least: Thanks a lot for answering and taking your time to help me. I've read a lot of posts here and am very grateful!