This website has a lot of examples of everything, really. It’s not all worthy of a band 9, but there is some good information. This example is quite strong, although the use of paragraphs is not completely logical.
Here is a table with some useful vocabulary for describing trends. (Avoid “go up” and “go down” by using more academic words)
This is a page that has some corrections of mispronunciation of common words that you may want to use on your test. Take a look:
This is a link to a really great table with all of the verb tenses in English. You’ve got examples in the affirmative, negative and interrogative. Really great stuff.