Image by HeyGabe, shared under a Creative Commons Licence
1. Sit down and shut the fuck up.
2. Your phone is not important during a performance.
3. Separate your personal feelings about an artist from their work. Love the art, hate the artist.
4. Write for the reader.
5. Listen to criticism of your work, but brush off the abuse.
6. Stay humble, no one wants to work with an asshole.
7. Be passionate about your work.
8. Fact check, fact check, oh dear Lord, fact check.
9. The only thing that should restrict your review is the word count.
10. A good critic can work around any word count,.
11. Going to a performance with an open mind and no expectations can lead to great experiences.
12. Remember that a review is not a stagnant piece of prose; it is a fluid work, it adapts, evolves and grows as you do.
13. Resisting change is futile.
14. Refusing to travel to “the regions” to see “regional work” will be your downfall.
15. Pay attention to what you’re reviewing; an alarming amount of ‘critics’ don’t.
16. Don’t write about yourself; the reader wants to read about the show, not your memories.
17. However, if you have a very relevant story to share, then by all means, share it. Just make sure that it’s relevant to the piece.
18. If you attempt to write a review that spends more time discussing how attractive or unattractive you find the actors in the piece, then you shouldn’t be a journalist, let alone a reviewer.
19. Try to keep on top of your emails, because some people will only email you once.
20. Don’t draw attention to yourself while you’re working. It’s off-putting to performers and it makes you look like a tool.
The Taylor Trash 
Sounds like a lot of work! You forgot ‘don’t fall asleep during the performance’, or is that not problem in theater? I really enjoy classical musical, but when I finally went to a symphony I passed out like halfway through.
Also, what are ‘the regions’? Like rural areas or the highlands?
I should add: “Don’t fall asleep and don’t drink too much, dammit!”
The regions are anywhere outside of the big cities, so rural areas, and in the case of Scotland, the Highlands, the Borders etc. There are some London critics that consider anything outside of London as “the regions” and some even refuse to review outside of London, which I feel is a mistake.