Gruff Rhys: I wouldn't say no to anything (except, perhaps, driving a van on acid)

I don't think of Glastonbury as a place not to do things – maybe it's a place to not worry about seeing anything in particular, just wander around chancing upon stuff and try things out you wouldn't usually do. When I played there with Super Furry Animals in 1999, some guy on acid tried to drive a van through the audience. It was incredibly dangerous. He got 100ft from the stage before he gave up due to the volume of people – who climbed on top and started to use the van as a podium. He went nuts and tried to throw people off. And when that didn't work, he just joined in, dancing on the roof. We were playing a 20-minute version of The Man Don't Give a Fuck with members of Mogwai dressed as aliens, with fists in the air – the international sign of protest. It was utter chaos – but beautiful – as this violent van driver got, as Stephen Stills would say, "loved out of the situation" by the rest of the crowd.

Gaz Coombes at the World's End film premiere. Photograph: Jonathan Hordle/REX

Gaz Coombes: I wouldn't fly in to the site

As a new artist, I wouldn't turn up to Glastonbury in a helicopter, with Wagner's Ride of the Valkyries playing through loudspeakers. Unfortunately, when I was in Supergrass, we did exactly that. It was our first-ever Glastonbury in '95, and a music paper provided us with the aircraft. When we started hovering over the site, everyone looked up, thinking we were the Rolling Stones. As we landed, all these photographers leaped out first and had just started snapping away when then these three little lads with bare feet got out. You could see the disappointment in people's faces and hear them going, "Who are they?" It was a weird mix of embarrassment and thinking, "Yeah, we've made it!" Also, I wouldn't wear see-through plastic trousers, as Iggy Pop once did at a festival we were playing at. His transparent trousers actually steamed up, like the inside of a car on a rainy day. He got the crowd onstage, so I ended up right next to him. I was dying to write something cheeky in the condensation.

John Newman: 'I want to be the naive, creative person who loves the job he’s doing and continues to do that for a long time.' Photograph: Rhys Frampton

John Newman: I wouldn't come home as a hippy

Playing at Glastonbury is like the Ivor Novello of live music. It's the big one. I did an acoustic performance at Glastonbury last year and spent most of the weekend there. It was amazing, because I'd never been before, but I found it weird. Half of my friends came back as hippies. My mate Max is the biggest geezer. He went there talking all like this: "And I'm gonna see some naked women there an' all, like" and came back all touched with the earth. He'd really found himself. I love all that sun circle thing, but it's for other people. I'm not expecting a spiritual experience. I'm also not planning to walk onstage naked, because my mum will be watching it on the telly.

Faris Badwan at Field Day Festival, London, 2014. Photograph: Ollie Millington/WireImage

Faris Badwan of the Horrors: I wouldn't wear a hat

I will not be wearing a hat. My mum's border collie, Ruby, has a real problem with people wearing them. Hats make her first suspicious and then agitated, and they provoke a similar reaction in me. I'm not just talking about festival hats. Trilbies, baseball caps, fedoras – the way they sit on their lofty perch, openly mocking you. There's not a single hat in existence that hasn't sent me into a violent rage.

Ricky Wilson at a Lamborghini launch, 2014. Photograph: David Fisher/REX

Ricky Wilson of Kaiser Chiefs: I wouldn't be a professional festival-goer

Around May, I start getting asked what my "festival essentials" are. I usually mumble something about it being the rest of the band. Surely no one actually cares if Pete Wentz takes wet-wipes or if Plan B recommends Kendal mint cake? But there are some people who do – the festival professionals. They wear a waterproof poncho, fishing hat and factor 50 on their nose, like cricketers. Tin cups and toilet rolls dangle from their rucksacks and the running order is worn round their neck with highlighted "must-see" acts. They are determined to make the most of it, but end up weighed down with so much shit they've lost sight of why they registered for tickets a year earlier before a single band was announced. The truth is, this is not the way to have a good time. You can't treat a festival like a job, shuffling from stage to stage, seeing everything but totally missing the point. The festival professionals tut at the kids sliding half-naked through the mud, as if they haven't got a clue how to do festivals properly. Sure, there will be half-naked kids who might face regret at some point on Sunday afternoon, but if they can remember it, they won't forget it. So the thing I'd never do at Glastonbury is read a list of musicians' festival essentials before I get there.

Photograph: Ray Tang/REX

Nick Mulvey: I wouldn't get stuck in a toilet

"I wouldn't want to get stuck in a portable toilet again, as happened to me at one Glastonbury. It was late, dark and incredibly smelly. It opened fine – but then I couldn't get out. I don't know if someone had played a cruel prank on me, but the door just wouldn't open and I ended up banging and shouting for someone to free me. The big fear was that they would have to tip it up to get me out, and I'd be covered with poo. Also, at this year's Glastonbury, I won't be wearing my brown-bear onesie anywhere near the Pyramid stage, for fear of being shot at by members of Metallica.

Patrick Carney onstage at Reading Festival, 2012. Photograph: Kevin Nixon/Future Publishin/REX

Patrick Carney of the Black Keys: I wouldn't do magic mushrooms

This will be our second time at Glastonbury, but the little we saw in 2010 was fun. We played after Tegan & Sara in a tent, and that was as far as we got. So I still haven't seen the Pyramid stage. I would definitely never do 'shrooms at Glastonbury. In fact, I wouldn't do any drugs. The idea of doing drugs around 180,000 people really freaks me out.

Russell Marsden of Band of Skulls: I wouldn't be uptight

The great thing about festivals is you can make your own fun, so the thing to definitely not do at Glastonbury is come away having not enjoyed yourself. We've been quite sensible on tour this year so Glastonbury is going to be my date with debauchery. I've done quite a few things at festivals I've regretted afterwards but usually only heard about them from people who were there, so I'm hoping that will happen again. I do remember our first time at Reading. It was quite rainy and they'd put wood chips down to make it look nicer, but they'd landed on liquid mud. I leapt from pretty high up into this mixture, and just walked into the media tent covered in it, the terrifying spectacle of a mud-and-wood man.

Stuart Braithwaite of Mogwai: I wouldn't hang around the VIP areas or demand a private loo

I don't think I'll have my own private toilet. I remember Nicky from the Manics had his own toilet one year and everyone gave him a really hard time. He's one of the nicest people I've ever met, so I'm sure it wasn't through malice, but I definitely won't be making any lavatorial demands. We once did a festival in Italy with Skunk Anansie and they had their own toilet and we were appalled. Somebody put a cruel rumour about that we are demanding 50 Kinder Eggs when we come offstage at Glastonbury, but it's completely untrue. Also, I won't pay to be a VIP or do that meet-and-greet thing – where fans pay to get a photo taken with their heroes. Avril Lavigne did it recently and wouldn't let the fans stand any closer than two metres. Mind you, I'm not sure anybody would pay money to meet us.

Charles Cave of White Lies: I wouldn't forget the name of the festival

We're definitely not going to shoot any bears, because people are getting rather upset about Metallica's James Hetfield's involvement in a hunting programme on TV. However, mostly, we won't go unprepared. You need to make sure you've got dry clothes and baby wipes. If you lose a personal item in the communal bathrooms, do not attempt a rescue mission. Any kind of festival scuba-diving in that department is not encouraged at all. The most important thing at Glastonbury is to remember where you are. Hopefully we won't walk onstage and say, "Hello, Download!"

Adio Marchant of Bipolar Sunshine: I wouldn't worry about keeping in touch on my phone

When I get near Glastonbury, I'm definitely going to turn my phone off. Everyone will be calling me, but you don't want to spend all day on the phone at a festival, so I'm going to set up a status update saying: "I am at Glastonbury, stop calling." To make sure I can find my friends when we all get lost, I'm going to suggest a meeting point: stand next to the funny guy in the clown outfit. The problem is, at Glastonbury, there are about 10,000 funny guys in clown outfits.

Becca Macintyre of Marmozets: I wouldn't play any covers

We're headlining the BBC Introducing Stage, but we won't be playing any covers. It's like you're saying: "Our songs aren't good enough, so we'll do a cover so people will jump around." The last one we did was Morrissey's Irish Blood, English Heart. We actually got an email from him. He said, "It's the best cover that anyone's ever done." It's very tempting to play that at Glastonbury just in case Morrissey's watching us on the telly, but we probably won't. And I won't be wearing those tiny little shorts that some people wear onstage, with people pointing cameras. It's disgusting! Last year, as a punter, I wore glitter on my lips. I've never eaten so much glitter in my life.

Photograph: Dave J Hogan/Getty Images

Lauren Mayberry of Chvrches: I wouldn't go unprepared

I'd never say never to anything, although I'm not really a mad dance/slam tent type person. The worst thing you can do at Glastonbury is go unprepared, especially for the weather. We recently played a festival in Houston where it was really hot and humid, 31C or something. They had to evacuate the site for two hours because of storm warnings. We ended up sat in a portable cabin for ages, worrying that we were going to be struck by lightning. In the end it was very rainy, but not quite the expected apocalypse.