Don't waste your time ladling soup, Gordon - get stuck in to the difficult areas, such as bidding for local government services or fundraising.
That's the summer volunteering advice for the Prime Minister from Debra Allcock Tyler, chief executive of the training and publishing charity the Directory of Social Change.
"Instead of spending his time on the front line, he should do something like writing a funding application that tries to prove outcomes when they don't yet exist," said Allcock Tyler.
Downing Street confirmed last week that the Prime Minister would spend part of his holiday volunteering in his constituency, but declined to give details.
Alan Boyle, chief executive of training provider West Fife Enterprise, said environmental work and employability projects were hot topics in the area around Brown's Kirkcaldy and Cowdenbeath constituency.
George Thomson, chief executive of Volunteer Development Scotland, said the PM had a lot of experience that could really make a difference.
Volunteering placement website www.do-it.org threw up some intriguing volunteer vacancies in Brown's Kirkcaldy constituency and the surrounding county of Fife.
The Kingdom of Fife Railway Preservation Society is looking for a treasurer. The advert for the position on volunteerscotland.org.uk says it requires an understanding of tax laws and adds that "knowledge of budgetary control is desirable".
Community interest company Growing Ambitions, which gives career advice to students, is looking for volunteers to give 20-minute talks to students about their jobs. The only requirements for the post are "enthusiasm and a heart for young people".
Brown's local Girl Guides group is also looking for volunteers. The role could involve "outdoor adventures, enabling girls and young women to learn new skills" and "running shops and refreshment stalls". Another aspect of the work would entail "managing funds and helping make best use of resources".
Volunteering charity YouthNet is advertising for a voluntary "ranter" to write articles about "anything that's got on their wick". According to the advert for the position, "the angrier the subject makes you, the better".
WHAT THE EXPERTS SAY
"Brown doesn't really get volunteering. I'm concerned he'll kill the baby by co-opt-ing volunteering into the state" - Laurence Demarco Founder, social enterprise network Senscot
"Public services need volunteers. Brown could try helping out in schools, hospitals, prisons and mental health services" - Dame Elisabeth Hoodless Executive director, CSV
"Brown is used to having a lot of responsibility and a small budget, so he'd make a great volunteer manager" - Debbie Usiskin Vice-chair, Association of Volunteer Managers