Not every book you read will be a favourite. Sadly, there will be books you will not like, will not connect with, and will want to throw against the wall. Some you may even want to burn.
Decide right now what type of review you want write. Will your reviews rip into an author and tear them and their book apart? Do you want to be a reviewer who only writes positive reviews? Will you either love everything or hate everything?
No matter the decision be honest and be consistent. Stand by your words.
If you are going to be blunt and possibly rip the book apart, you probably don’t need to read any further. The only suggestion I can offer is at least back up your opinion. Give a reason for your negative review.
And, that is exactly what a non-glowing review is—a negative review. You are about to tell an author you did not like their work.
Be honest. No one benefits from sugarcoating or wishy-washy excuses.
There was a reason you accepted the review request, what happened between that and the final reading? Was the story idea good but wasn’t fully explored or developed? Did you find yourself not caring about the characters? Is it as simple as just not mixing with the book?
Was there anything positive about the book? Include this information, too.
In the end, all you really need to write is a summary of the story including what didn’t work for you and what, if any, positives there were. Feel free to acknowledge this is just your opinion. Suggest the audience you think may enjoy the book.
But, always stand by your words.