A local print shop made this for me as a poster before I started following the tour through the UK
If you like it, feel free to use it for anything.
In the UK I saw loooots of little girls dressed in the 'blue wig way' which was cute but not up to date - but what was really impressive was being dressed up as the queen of the jungle from Roar, from flower crown and black long wig to the leaf skirt, that looked really amazing.
Also, one way of just getting a present, letter or something to Katy is hanging out in the RS (need a ticket, of course) before the opening act and in between the opening and main act. You could meet - not Katy - but someone of her team that way easily, and if it's a band member or Tamra they're likely to take something backstage for you; Josh, the bass guitarist, did that for me, and I've seen tweets of others who met other Katy-people the same way.