To an indie author, and an artisanal publisher, reader reviews are gold. I love to hear what you think, what you like, what could have been better.
Reviews do NOT need to be 350 words, crafted as the result of agonizing over the text, poring over the references, and then beating yourself up trying to come up with words to describe your feelings. "I liked it," is a perfect, three word review.
If you must write more than three, words, think about who would like to read this book, and say that.
But if you already know what you are going to say, go for it. Think about posting your review on Amazon and on Goodreads, and on whatever other blog or website you feel like posting it on. I will be eternally grateful. If you let me know about your review, I will thank you on social media.