The good news is that you have been doing this all year and for your entire schooling so far! However, if you want to do some specific skills practice before the exams, we suggest:
Spend time each day working on your Learning Journey on Writer's Toolbox. Working through the Learning Journey modules will be excellent preparation for the Writing exam and also help you with some parts of the Reading exam. This is because it will help you to learn and revise your sentence structures, grammar and punctuation, as well as helping you with language features and figures of speech you need to know for reading.
You could also go on to Education Perfect, where you will find specific content aimed at the Literacy exams. Just go to English & Literature/Browse all content and scroll down until you find NCEA Literacy: Reading (US32403) or NCEA Literacy: Writing (US32405).