1. Never underestimate the importance of a nice cup of tea. The success of a concert seems directly proportional to the alacrity with which the performer is offered refreshment backstage when he/she arrives. A well-run venue will offer its artists a cuppa pretty much as soon as they walk in. If you have to ask if one is available and the response is "No", chances are that your concert will be a washout, and not just because you're thirsty. Venues: remember, you never know when your performer might turn out to be, in fact, Miss Marple.
3. Be organised about your home life. Make sure you've fed your partner/kids/cat, watered any plants, turned down the heating, locked the back door, put the bins out, switched off the oven, unplugged the TV, ironed enough clean clothes for your trip, washed your concert outfit, told the neighbours the dates you're gone, and so on. If you're all sorted at home, you'll be able to relax and focus on your job without suddenly thinking, "Oh my God, did I leave the oven on?" in the middle of the Chopin B minor Sonata.
4. Plan ahead. If going by train, book faaaar in advance to get an affordable ticket - you might even have some fee left. Never agree to travel in a car if you don't trust it or the person driving it. Always plan to arrive earlier than you need to, in case of delays such as signal failure, leaves on the line, sheep on the motorway, etc. Besides, arriving at the last minute may leave you too muddle-headed to notice what's actually going on under your nose.
5. The harder you have to slog to get bums on seats, the less successful your concert will be. A poorly run venue will show no interest in promoting your concert and probably won't even have a piece of paper up saying it's happening. A well-run place, though, will most likely have an established, loyal audience that trusts it to offer good events. What's true at the bottom will probably be true at the top (see Miss Marple, above).
6. Switch off your mobile phone. You think it's embarrassing if one goes off in the audience? Try having it happen on stage.
8. If you have to stay over somewhere, do not trust internet reviews. Get a personal, word-of-mouth recommendation. [Come to think of it, don't trust the internet for anything, ever, let alone bloggers ;).]
9. Put your work on a proper business basis that accords everybody involved the respect they deserve, clarifies the financial position from the start, and doesn't confuse the issue with personal angst, guilt-tripping, pressurising, and so forth. Stand up for your rights. If you don't, you've only yourself to blame, because you're being too nice...
10. We are mostly too nice. If we are too nice, we are used, exploited or walked upon. Or, in some cases, skated upon. Here's an extreme example. The Southbank Centre, as leaseholder of its land, would be perfectly within its rights to send in the police to clear the crumbling skate park so assiduously supported by our mayor - but it has always been too fair-minded and too nice to do that. The bottom line, though, is that if they can't get at the space to repair it, the QEH will eventually become unsafe and will be forced into disuse, which wouldn't even be good for the skateboarders.