But I do have to say, as someone who reads all of the reviews that leave the office, anonymous reviewers have been no less diligent and professional than the reviewers who signed. And the very few that have serious problems are caught in the editorial process and addressed.
Three links mentioned in the comments are ones I've read and liked in the past, so I thought I'd repeat them here:
- Ten tips on how to write a good peer review in any field from the Guardian: http://www.theguardian.com/higher-education-network/blog/2013/sep/27/peer-review-10-tips-research-paper
- And though I have referred to this before, there is this extensive look at peer review and how to write a review from the British Ecological Society: http://www.britishecologicalsociety.org/wp-content/uploads/Publ_Peer-Review-Booklet.pdf
- Results of a survey that Molecular Ecology did about signing reviews: http://www.molecularecologist.com/2014/04/do-we-sign-our-peer-reviews-mostly-n