Emeli Sande has to be in the "right place spiritually" before she performs live.
The 'Hurts' hitmaker has learned two important lessons over the years that cutting back on alcohol and meditating before shows is the most valuable practice pre-show ritual for giving her best performance, although she admits she loves the odd glass of bubbly.
Speaking at BBC Radio 2 Hyde Park, she said: "Warming up is very, very important. Trying not to drink too much is a very good idea.
"Sobriety... I like a bit of champagne. I guess trying to stay healthy as much as you can, meditating and getting into the right zone to be on stage.
"Going on every night you really have to make sure spiritually you are in the right place. That's been the biggest lesson for me."
The 30-year-old Scottish singer's next gig is performing for Sofar Sounds' forthcoming concert series Give a Home on September 20, to raise awareness for the global refugee crisis.
Emeli will have the honour of performing at media mogul Richard Branson's son Sam's London home and she is hoping to debut a new song live.
She exclusively told BANG Showbiz: "I just love doing gigs that intimate. We are going to do a few acoustic versions.
"Potentially I have a few a new song coming out later this month, so hopefully we get to do that song.
"I love it when everyone can just sit on the floor giving a little performance.
"You can get really deep and soulful in your delivery."
Ed Sheeran will also be performing in Washington D.C. on the same day hosted by Richard's daughter Holly.
Hozier, Moby and Laura Mvula were recently added to the line-up.
Other artists playing in the concert series at top-secret venues around the world include Archive, Blaenavon, Get Cape. Wear Cape. Fly, Imelda May, Jon Hopkins w/ Leo Abrahams, Marika Hackman, Nick Mulvey, Sivu, The Hoosiers, To Kill A King and We Were Promised Jetpacks.
And previously announced were Above & Beyond, Eliza & The Bear, James Morrison, Jessie Ware, JP Cooper, KT Tunstall, Nina Nesbitt, Nothing but Thieves, Rudimental, Sampa the Great, The Jezabels and Wild Beasts.
The funds raised will support Amnesty International's work in documenting human rights abuses and violations against refugees and pushing governments to find a sustainable solution.
More than 22 million people have been forced to flee their home country, so the aim of the ambitious concert series is to unite people in showing solidarity with refugees.