Credit: Paul Saunders' Glastonbury t-shirt design (above)
There was this website I found based on a 2008 edition of defining the top three things to bring to a festival.
The first one was some chewing gum or any mints. This isn't actually on anyone's first priority but it's good to bring some especially for dental hygiene. Pungent festival breath consists of 90% beer vapour and 10% essence of falafel.
The second thing is a festival t-shirt. Any fashion conscious visitors will know that a festival t-shirt is a must have for the 'festival look.' In 2010, Glastonbury did a competition to design the festival's official t-shirt to celebrate the 40th Anniversary of the festival - winner gets £1,000 and a pair of tickets.
The third thing is a lightweight waterproof poncho - this is just in case it rains because no one really knows what the weather could be like...whether it could be really hot, or cold, and it could possibly rain. So just to be on the safe side, a raincoat or poncho would be a good idea to carry. Possibly...designing a waterproof poncho, especially designed for festivals could be a good idea.
I thought the fourth thing could be sunscreen that is an essential product to a festival. I think a lot of visitors who go to festivals, may forget to remember to bring essential things like sunscreens to help protect them from sunburn or it may be at the top of their list. Perhaps we could possibly work on the idea of providing a sunscreen spraying booths for visitors.