It is also critical to always be professional. If you are going to criticize something, it is vital to ensure that you criticize intelligently, thoughtfully, and that you provide examples to back up what you are saying. Simply panning something without providing specifics is not helpful to your readers, or to the promoter. I ve never actually had any negative reaction from bad reviews that I ve written, although once a publisher phoned me after I d published a bad review and when he told me his name, I immediately asked him if he was calling to tell me off. As it happened, he actually told me how pleased he was with my review and praised my candor.
Most publications manage their own titles.
They will be on publishers' mailing lists for the audiences they have and they will send out titles to their reviewers. That is always a bit of a gamble, but sometimes you can get away with it if you are experienced enough and have something of a following with the publication. Of course, if you have your own publication, you can review what you want. There are quite a few websites which take unsolicited contributions, and of course you then choose what you want to review. It can be harder to obtain review material, though, if you can t cite where you are going to publish.