A very common feature in IELTS essays is the personal pronoun (I, we, you, etc) and that needs to change. The IELTS is an academic exam, and in academic English we try to avoid using personal pronouns, which are really more common in spoken English.
Why not use personal pronouns?
Personal pronouns are a feature of regular, common speech. They are used frequently in spoken English (much more frequently than most East Asian languages, for example), and using them correctly is a sign of English fluency.
However, in writing essays we typically strive for objectivity. We want to sound unbiased and informed. The purpose of an academic essay is present complex ideas in a serious way, and personal pronouns make it sound rather personal and casual.
How to avoid personal pronouns
Avoiding the use of personal pronouns in your IELTS essays is a very easy way to make your essay seem much better. Therefore, you should consider consciously cutting down on the use of I, we, and so on.
In the IELTS Writing Task 1, you will be required to write a report on a trend of some kind, and there is absolutely no need to ever involve your own personal opinions. There should never be a personal pronoun included in this section. You should be using a detached, passive voice for this section, and refraining from stating anything other than what you can see in the information presented.
In the second part of the exam, you may well need to give an opinion, in which case you can use personal pronouns. However, for most of the essay you should try to maintain a balanced, objective perspective. You should look at your sentences and ask yourself if it is possible to remove the personal pronouns. In most cases, it is.
What’s wrong with this passage?
Climate change is a big threat to our planet and we really should take measures to stop it before it gets worse. I heard that one of the major causes is air pollution from factories, so I think our government should set laws to restrict emissions. If they do that, then we can all live a much better life.
There are far too many personal pronouns here, and they could easily be removed to make the writing appear more academic.
Take a look at this improved version:
Climate change is a big threat to the planet and, if humans don’t act quickly, it will only continue to get worse. According to various reports, one of the major causes is air pollution from factories, and the responsibility falls on the world’s governments to set laws to restrict emissions. If this happens, climate change should be abated and living standards will increase across the globe.
The content of the second passage is essentially the same, minus a few embellishments at the end, but the main difference is the impersonal tone brought about by the lack of personal pronouns.
There is an updated version of this post here from 2019. It has much more information about how to avoid personal pronouns in your IELTS essay.