Hi! Easiest ones to do are probably going to be speech, letter, or article (if neither of the above). With that in mind, make sure to always consider your audience. Sometimes it tells you who to write/speak to, but even if it doesn't just decide on adults or students or at least something to anchor your tone- don't alternate too wildly between formal and casual as it makes your writing less fluent. Some good persuasive techniques include rhetorical questions, anaphora (starting consecutive sentences or clauses with the same word or phrase) and strategic use of 'you' or 'we' pronouns. Something incredibly important is your sentence length. Use long, middling AND short sentences. Short ones are good for impact, but using them too much makes the writing stilted. Some fun little extras that examiners like are things like a cyclical structure (shows a well thought-out answer, even if you didn't plan), fake little personal anecdotes, fake statistics, and 'experts'. Always try to include at least one statistic and one expert. A good example would be 'a study conducted earlier this year on the topic of _____ by Dr. Henry Robertson from the University of Glasgow showed that 34%...' or whatever name or university you can think of. Putting in little details like this makes it seem so much more real and legitimate. Also remember that in a letter or speech you must start with an address, and sign off at the end of a letter. 'Yours sincerely' is usually a good bet. Best of luck!