Go back to your project proposal, and reflect on whether you were able to carry out your project in the way you intended. This evaluation will be much easier if your original project proposal included a detailed schedule.
Writing your reflection will be much easier if you keep a project log.
Record what you do as you do it - in whatever format is easiest for you, whether in a paper notepad or on your PC or your phone. The notes don't need to be long. Each time you do any work on your project, write down:
1. What have I done today?
2. Why did I do it like that? (ideally this should link with research you've previously read)
3. How did it go?
4. Where do I need to go next?
If you do this as you go along, it will give you a rich source of data for your reflection section, reminding you of things that you'd previously tried and might have forgotten about by the end of the project.