Certain tasks in IELTS are more predictable than the others. For example, we know that in the Listening module there is always at least one part related to education and academic knowledge. The Reading module in General Training also features topics that are fairly predictable, and there is no reason to not prepare well for them.
For some candidates, it’s very tempting to write as much as they can in the one hour given in the Writing section — they want to really showcase their range of vocabulary and their ability to write long sentences. But do long essays really get you a better band score?