Make a list of what you consider important in a festival. Think music style, festival location, crowd size, food and amenities. Consider how comfortable you are with large crowds. For example, you can rub shoulders with over 175,000 people at Glastonbury, or opt for a smaller crowd of under 7,500 at the Wychwood Festival.
Decide what type of festival you want to visit. If you're looking for music festivals, choose between pop, rock, folk or dance genres--among others. Literary and arts festivals include the Hay Festival of Literature and the Edinburgh Festival of Performing Arts. Decide whether you want to camp or stay in a hotel. Many festivals take place in town or city locations with nearby hotel rooms.
Log on to the Efestivals and Virtual Festivals websites--the two largest festival sites in the UK. Look for recent reviews and recommendations, as well as the latest band line-up rumours and confirmations.
Check the current winners of the annual UK Festivals Awards (see references below). Categories include best overall festival, best small festival, best newcomer and even best toilets.
Don't assume bigger always means better. Smaller UK summer festivals such as Bestival on the Isle of Wight, Green Man in Wales, and the WOMAD Festival in Wiltshire frequently win awards and good reviews for their events.
Check annual festival guides from national UK newspapers such as the "Guardian", "The Independent" and the "Times". Guides often offer an up-to-date assessment of the best new festivals and current trends.
Look to the Continent. Europe has many popular festivals, including Roskilde in Denmark, Exit in Serbia and Benicassim in Spain.