A good summary as to why reflective practice is important and how it can be improved is provided by the University of Kent:

https://www.kent.ac.uk/learning/PDP-and-employability/pdp/reflective.html

There are different models that can be used to structure reflective writing. Leeds Beckett University provides a useful overview of the most important ones:

http://skillsforlearning.leedsbeckett.ac.uk/preview/content/models/01.shtml

One model that provides a particular clear structure for reflective writing is Gibbs’s Reflective Cycle. Oxford Brookes University provides an overview:

https://www.brookes.ac.uk/students/upgrade/study-skills/reflective-writing-gibbs/

For more detail, see:

https://www.kcl.ac.uk/campuslife/services/disability/onlineresources/StudyGuides/USING-GIBBS-REFLECTIVE-CYCLE-IN-COURSEWORK-DEC-2016-P-LIA.pdf