Here's my strategy :)
1. structuring (based on question types and word limit)
->2. brainstorming ideas
->3. bullet points
->4. adding details to each point
->5.organise ideas (identify relationships of different ideas[such as cause&effect, comparison...]/using symbols, such as "->" to connect ideas)
(Planning stage)
->6. write (You may think about linkers, pronouns, synonyms, parallel expressions, topic-related vocabulary, sentence structures, antonyms, paraphrasing, summarising... when you are writing)
->7. proofreading
->8. polishing
It's a good strategy. Some of the people writing for IELTS have difficulty organising a piece of writing (some native speakers of English would also have that problem!)
If it's a university assignment, you may also need to consider referencing.
