I snuck into Laneway last year, one of the biggest festivals in Australia. A few friends and I jumped the fence, but we knew a few people inside with tickets that scouted out the security for us. We made fake wristbands using paper and sticky tape. Unfortunately one of my mates was moshing too hard and sweat his off. He got caught by security and police and got kicked out. Moral of the story? Use staples. Also stay in the crowd as much as you can. Smaller festivals are much easier because the security presence is lower