If you are preparing for IELTS, one thing that you definitely can’t avoid is the writing section. It is often the pain point of majority test givers. Though it doesn’t mean that it’s not possible to achieve 8 band or above on IELTS writing.
With the right understanding of what is being tested, how to approach it, one can absolutely do well in IELTS writing Task 1, both Academic and General.

IELTS Writing Task 1 - Academic Module
Requirements are pretty straightforward, you are given a total of 60 minutes to complete both the tasks, out of which you can conveniently assume to dedicate around 20 minutes to IELTS Writing Task 1. It is suggested that you spend around 20 minutes on Task 1 and write MORE THAN 150 words, which is the word limit given by IELTS test makers to test takers.
Writing task 1 in an academic module is about writing a report that requires you to study data and articulate it into an article, ‘not essay’. Data will be presented to you in either of these 7 forms:
Bar chart(s)
Pie chart(s)
Line graph(s)
Table(s)
Map(s)
Process chart(s)
Or a combination of either of the mentioned above
What does IELTS test in Writing Task 1?
In this part of the test, you will be tested on your ability to objectively describe the information that is given to you in one of the forms mentioned above, you will need to compare and contrast on different ideas that can be extracted front the data. You will need to report on an impersonal topic without the use of any opinion of yours. It is important that you use the language of data description, which means that you don’t have to be all descriptive on ideas other than the data that is presented to you. Do check how you connect the data with this description because how you form this description is going to be significant on your score in this section of the IELTS exam.
How is the article scored?
According to the test makers, both article (IELTS Academic) and letter (IELTS General) are tested on the following criteria:
Task Achievement
Completing the task that is assigned to you, identifying the type of questions being asked making sure that you stick to the point while answering the question
Coherence and cohesion
Whole answer, whether it is an article or an essay should be coherent in terms of meaning that you are trying to convey and you should be switching between ideas swiftly
Lexical resource
Though vocabulary is an important part of the IELTS writing exam but more than vocabulary, how you are able to showcase your ability to use different words to convey the same meaning is valued. Paraphrasing skills are also included in this
Grammatical range and accuracy
Grammatical mistakes can cost you score in IELTS, so you must try to avoid any grammatical errors while completing the task
Each criteria carries 25% of the weightage. You can be advised to take care of each of the criteria and focus on all areas equally. Make sure to evaluate yourself in all of these four categories and avoid using any kind of pre-written drafts.

Source: ielts.org
You can also check about the IELTS writing test 1 format briefly.
How can you improve in writing task?
Writing task is challenging not only for the non-native speakers but native speakers as well. The reason is that since our school days, we have been asked to express our opinion and narrative on the writing tasks but this is not the case in IELTS. Here, you will have to force yourself to fit your ideas and given data into the scoring scheme of the IELTS exam. Here, this is why there is maximum disparity in IELTS scores on writing exam, specifically because what you say doesn’t matter, how you say doesn’t matter, the way you say your ideas, changes the whole game.
You are advised to read the question very carefully, so that you understand what is actually being asked. Don’t skip this step at any cost. Don’t start writing without analysing the question properly because that’s what people usually do and it makes IELTS people easy to score you low. It is important to select the important information by comparing and contrasting. You must be able to understand the overview of what data has to say and should be able to articulate and write into the right words.
Do categorise the data on the specific so as to create the contrast and structure it well when you begin writing it. You should analyse the question well and writing down the important features (in a separate space) is certainly going to help. You can practice with a certified expert with a big pool of practice questions and mock tests or check some sample questions (Source 1, Source 2, Source 3, Source 4) and use all tips mentioned in this article to understand how to score 8 and above.
IELTS has officially provided some samples like the one mentioned below (Source 1), comment is given by official IELTS examiner:


Why is structure important?
Structuring abstract ideas is one of the key measures that IELTS tests you on, so it is important that you structure your article well. It goes without saying that you should paraphrase (writing the question prompt and data into your own words). Mentioning the overview tells the examiner that you are able to create a holistic picture about the data and are able to present it as per their measuring standards. You don’t need to extend your article in more than three paragraphs since you are supposed to summarise in 150 words only.
IELTS Writing Task 1 - General Module
IELTS Writing Task 1, general module is about writing a letter which could be formal, semi-formal or informal in nature. The letter should be constructed in a specific way where you must mention the reason for writing (also include the paraphrase). You will need to answer the bullet questions in respective paragraph(s) where you should use cohesive devices and different types of sentence constructions. You can end the letter with a closing statement where you express the courtesy (Looking forward to hearing from you… etc). At last, a proper sign-off is needed as per the type of letter you are being asked to write to (Yours sincerely, Yours faithfully, Warm regards etc.).