When Lee Denny's parents went on holiday four summers ago, the 17-year-old was left with one strict instruction - do not throw a house party.
Denny kept his word - and staged a music festival in the back garden instead. He named it after himself, placated his parents and LeeFest has taken place every year since.
With a festival boom over the last decade, many such back-yard bashes - which started life as parties for mates - have evolved into fully-fledged festivities attracting thousands of fans and big-name bands.
Forty years after Michael Eavis decided to stage a gathering near Glastonbury, the organisers of three new homespun events explain how their festivals were born.
Facing the prospect of a long, dull summer before university in 2006, one of Lee Denny's friends uttered the words: "Let's do a music festival."
"We just phoned up loads of bands and all my friends came and moved into my house," the young impresario recalls. "We set up camp - we put a big table in the sitting room and set up a big office. It was great fun."
About 150 friends and friends of friends descended on the house in West Wickham, Kent, to watch a flock of local bands (including one featuring now-hot producer Starsmith).
Afterwards, the physics student and his co-conspirators attempted to cover their tracks before his parents returned.
"We spent a lot of time cleaning it up. But I think one stray beer can gave it away," Mr Denny recalls.
What did his parents say when they found out? "Yeah, they weren't so happy," he admits. "But we raised a lot of money for charity and we tidied it up really well.
"So they were all right and I managed to convince them to let us do it again the second year."
LeeFest has become an annual fixture, growing each year and moving out of the back garden in 2008.
Last year, the event was named best grassroots festival at the UK Festival Awards, and this summer will be the biggest yet, attracting indie favourites The Futureheads - with three top 20 albums behind them - to headline.
So is a festival a good cash cow? "Money? No," Mr Denny scoffs. "If you're looking to make money, I'd say there are probably easier ways than a music festival. But we're not setting out to do that anyway."
A non-profit event, LeeFest raises funds for the Kids Company charity. Mr Denny spends most of the year organising the festival, taking part-time jobs on the side.
The teenage dreamer in Mr Denny returns when he is asked for advice for other budding festival organisers.
"Do it - go for it," he says with a grin. "It's well good fun. Make your stage out of something and get all your friends and have a good time. Hopefully the sun will shine and it will go well. You never know what it could lead to."
LeeFest takes place on 14 August.
Seven years ago, Simon Ford decided to get his old school band back together - and staged a festival in his garden in Chagford, Devon, for the occasion.
Around 50 people were there and Chagstock has since taken on a life of its own, with a 5,000 capacity this year. Pop band The Hoosiers, who topped the chart with their debut album in 2007, will top the bill.
Mr Ford left his old life as a financial advisor behind after his event took off, and has put £150,000 of his own money into it over the years.
"I got to a point in my life where I either carried on wearing a suit and sitting in an office or went out and did something that I had a passion for, and I chose the latter," he says.
"I have to be a lot more frugal, but I'm a much happier person. I love what I do."
Squeeze headlined last year and Mr Ford says he tried to keep the intimate atmosphere as the event expanded into a new, larger site.
"It's turned into a full-time job but it's not going to provide me with a living," he says.
The event raises funds for Devon Air Ambulance and Water Aid, and is a not-for-profit venture. "Although that hasn't been a problem because we haven't actually made a profit yet."
There is one perk of running your own festival, though - Mr Ford's band play every year.
Chagstock takes place on 16-17 July.
"I never really had a plan to set up a festival," explains Alex Trenchard. "I had a barbecue for about 30 people with a set of decks, which went quite well. So we did it again the next year."
That barbecue celebrated Mr Trenchard's 21st birthday, in 2001, in the grounds of a 16th Century mansion owned by his parents near Standon, Hertfordshire.
By the third year, about 200 people turned up, although he was still learning the ropes.
"We built the stage ourselves and were a bit ambitious and built a big screen behind it," Mr Trenchard recalls. "It acted as a sail so the stage ended up blowing down the field with a band practically still on it.
"Things have got a bit more professional since then."
But that event saw Mr Trenchard really catch the festival bug.
"At midnight we cut all the lights around the stage for about three minutes. Everyone thought that was it, the festival's over.
"Then the lights went on in the adjacent field around a circle of trees and fireworks started going up. A torch-lit procession with people dressed as fairies led the whole crowd down to this secret area that no-one had expected, where a band were playing.
"It blew everyone's socks off. That whole experience really got me inspired about turning Standon into a festival."
The event now takes over neighbouring fields for the weekend and has gained a reputation for booking rising stars. Friendly Fires played in 2007, Florence and the Machine and Paloma Faith appeared in 2008 and Mumford and Sons performed last year.
And not even Glastonbury can offer an outdoor swimming pool, with music pumping out of underwater speakers and revellers swimming off their hangovers.
"Some people use it to avoid the shower queue," Mr Trenchard admits. "But we have a full-on pool party alongside it."
His parents, meanwhile, used to go on holiday to avoid the racket on their lawn.
But these days, they get into the full festival spirit, even dressing up on the fancy dress day.
"I never know who my mum is because she's one of the thousands of people in costume," Mr Trenchard says. "Last year we had a space theme and she was wearing a black wig and silver space outfit. She regularly comes up and surprises me."
Standon Calling takes place from 6-8 August.