In a way, stand-up feels like a young man's game - it's unusual being older, but it's better too. When I was younger, I just didn't have enough to talk about. Having some life experiences makes your material more interesting. But, yes, to a certain extent I'm still debating whether it's a fit job for a grown man - and whether my dad would be proud of me talking about genitalia on stage at my age.
You're touring a birthday show this time: Oh Fuck, I'm 40! How long did you spend preparing before taking it to Edinburgh last year?
I turned 40 in July and knew I was doing Edinburgh in August, so I had about six weeks. Fortunately, I write a blog everyday so I was able to use material from that. About half the show came from the blog. Knowing that you're writing for Edinburgh is quite an incentive - if you don't have anything ready in time, you're going to look like an idiot.
Presumably you tweak shows on tour?
Sometimes you just need to change one word here and there to take it in a new direction. There was a joke in Talking Cock that I thought was really funny but it didn't work over 100 performances. I literally changed one word and then the joke worked every night. Sometimes it's not a word, but an expression. The other night I did a gig and was really concentrating on subtle facial expressions to react to certain lines - the expressions brought something new to gags I must have already told 100 times.
I'd lose interest if I was doing exactly the same routine every night - and audiences can tell the difference between what feels new and what doesn't. I see the routine as a corridor: you're opening new doors and entering different rooms along the way.
How nerve-racking is it to improvise?
I like saying something without knowing what I'm going to say next, so I have to dig myself out of a hole. If the audience are being quiet, I'll sabotage myself sometimes to get a reaction out of them. It's a bit schizophrenic, I suppose.
I'm increasingly enjoying the freedom of veering off the script and not worrying about whether there's a gag coming up in the next 30 seconds. That's the best thing in stand-up. You get in a situation where you're not even sure what's coming up next and you end up with something really beautiful. Sometimes you'll struggle to write something and can't get the words right, but if you just get up on stage then it will come through instinct.
What about adapting to different venues?
Tons of things are way beyond your control - the roof's too high, they've got a band on before you, you're on a boat... But mostly you can adapt. Last night's gig was in an L-shaped room with the stage in the middle, so I sort of had two audiences - which can be confusing if you're doing a visual gag.
It's about experience. You have to learn how to play to 30 people - that's a really difficult skill. Once you've played to 30 people you can play to 5,000 people.
Do you watch other comedians on the circuit?
You've got to know what the mood of comedy is at a certain time. In Edinburgh last year, I noticed the shows were quite gentle and I thought maybe I'm going too far down the angry route, maybe it would be nice to be a bit more celebratory. I'm always trying out different tones, which might mean people lose a sense of who I am. But you can only do what you want to do - I'd rather take artistic chances than just pootle along in the same direction.
How have you learned to deal with hecklers?
A couple of times I've paid people to leave, which is a nice theatrical gesture. Most of the time, the rest of the audience hate the heckler - they're spoiling it for everyone else. You can generally use the audience against the person. Occasionally a heckler will actually be funny, and you just have to acknowledge that it's funny.
You've written quite frankly about overcoming paranoia and insecurity on stage.
I started doing stand-up when I was around 20. I wasn't terrible but I didn't really enjoy it - I decided I could only work with other people. The early Edinburgh experiences with [Stewart Lee] and the Oxford Revue were awful. We got a lot of flak from other stand-ups who were suspicious of the Oxbridge thing and bullied us. I lost my bottle a bit.
Over the last six or seven years, I've realised that I can perform on my own. I was really nervous at first, and getting a dry mouth, but I found my feet again quite quickly. It's simple: the more you do, the better you get.
· Richard Herring is touring Oh Fuck, I'm 40! around the UK from February 13. For details, visit www.richardherring.com