How to approach a Book Review Editor

I would like to build up my publication profile, including the writing of book reviews. I am not well-known by any means having just completed my PhD, though I am now working full time (contract) as a level A academic in research and teaching in my field.

I wanted to know whether it would be beneficial to approach the book reviews editor of a journal to see if they have any books in my field/subject expertise that require reviewing, and the best way to go about this.

This question/response here advises not to approach editors; however, in a publications workshop I took in 2013, I was advised that I should approach editors who often have a stack of books that need reviewing.