1. Don't write anything you wouldn't say to someone's face
Now, obviously it's difficult to tell someone to their face that you don't like their show, especially if they're seven foot tall and have anger management issues. Just remember that seeing a bad show isn't an opportunity for you to go to town on the metaphors. Last year's most controversial review was by a young writer who said "I'd rather stick a pool cue up my urethra than sit through this again". It's hard to imagine him saying that to someone's face and, if he did, the homicide would have been entirely justified.
2. But beware of Stockholm Syndrome
Other arts critics have an easy time, because they don't spend an hour locked in a room with their subject talking directly to them. When you're a comedy critic, it can be really difficult to criticise someone who is clearly a nice person. Stay objective. Review the show as it stands, even if you like the comedian more than their material. Similarly, there are a few unpleasant people who are also magnificent comics. It can hurt to give them good writeups but it has to be done.
3. Be daring when awarding stars
Awarding stars will quickly become your least favourite part of the job but it has to be done. Be daring. Giving a 1 star or a 5 star to something is a bold move that says a lot about you personally: what you like, what you hate, what you think comedy should be. Don't be afraid and don't hold these reviews back until you've got a feel for the festival. If the first show you see is a 5 star, give it 5 stars.
4. But around half of all reviews will be 3 stars
3 star reviews are awful. No-one reads them, no-one likes receiving them and you'll often have to award them to acts you really like. They'll also account for about half of the reviews you write. Star ratings follow what statisticians call a Standard Distribution, with a large peak in the middle. Also, about half of shows tend to be OK-to-good, which doesn't help matters.
5. Review the show in front of you
A key part of reviewing is to ask yourself two questions: what is this show trying to be, and how well does it succeed? Serious, thoughtful shows should be judged on how serious and thoughtful they are; daft, fun shows should be judged on how daft and fun they are.
The opposite of this is making too many exceptions. Sometimes you see how a show might be better if they just improved this or tightened up that. Be careful that you don't end up rewriting the show in your head and reviewing your own improved version.
6. But don't review the setting
You might occasionally have complaints about the room, the PA, the lighting or whatever. Sometimes these things might make the show unbearable and it's okay to mention that in your review. But remember your job is to judge the performance and you shouldn't penalise the performer for things that are outside their control.
7. Stay away from the big names
It can be very tempting to spend August in the Pleasance Courtyard. It's cosy and fun, and you can drop in to see the stars of the festival. Which is good for your career, right? All those big names in your portfolio.
Don't do that. There are people slaving away in every dive bar in Edinburgh and many of them are desperate for coverage. Go as deep as you can into the Festival. Search every nook and cranny and backroom in search of genius. Imagine how good you'll look if that Free Fringe act you reviewed ends up winning an award?
8. Don't assume that someone in a big venue is a big name
If you're new to the Fringe, you can be led to believe that everyone at a big venue is playing to a massive room with hundreds of people. They aren't. People play in sheds, broom cupboards, anywhere with four walls and a microphone stand. If you're at a big venue, scour the programme thoroughly. Great acts are often sitting right under your nose, eclipsed by bigger names.
9. Challenge your editor
Every publication works differently, but most of the time your editor will give you some kind of list of things to see. Challenge this. Seek out interesting shows and offer to cover them, if no-one else is. Or go see a free show and submit a review for it - even if the editor doesn't want it, nobody's lost anything. Editors try really hard to keep tabs on everything but we still rely on feedback from the guys on the ground.
10. Be really, really nice to your editor
Getting your review online or into print represents a certain amount of work for your editor. Multiply that by the number of reviews submitted and it quickly becomes a never-ending nightmare. Help your editor as much as possible by submitting clean, well-formatted copy on time with any supporting information required. Be as helpful to them as you can and they will love you as if you were their own child.
11. Do try and write with a bit of flourish
The reviewers role, first and foremost, is to be a writer. Be funny, daring, provocative, take risks and try to engage your readers. You're not writing product descriptions for the Argos catalgoue, you're trying to start a dialogue about the maddest and silliest artform in the world. Push yourself as writer. Try to make people feel excited about the Fringe.
12. But don't make it all about you
You're writing a review and the thing you're reviewing should be at the heart of it. Readers should come away from it with an understanding of what the show is like, not what an awesome writer you are. The trick is to find the balance; devise an approach that compliments the show and brings out its key elements.
Follow Bernard O'Leary on Twitter: www.twitter.com/SkinnyComedy