I don't go to festivals its not really my thing but i love all the fashion the shops bring out in celebration of them!
The three main shops that I've noticed that have some really nice stuff in that section were Republic, Miss Selfridge, TopShop and Jane Norman (though not for much longer for them!). I've Noticed that this sort of string stuff with tassels is in this year as well as waist coats. I love This and I saw a Gorgeous one in topshop for £40. Republic has theses fabulous bright coloured wellies for the mud. Gold chunky jewelry and maxi dresses to finish the perfect festival wardrobe.
I especially Like the Maxi dress and Gold earrings the earrings just pull the outfit together and the maxi is so elegant but just makes a perfect festival outfit!