First of all, this question has been all over fanpop so you could have actually found it.
But anyways, here's my answer - you gotta post images, videos and contribute as much as you can, post picks, comment on posts etc. People commenting and fanning your posts is also a help. This way you can get a medal.
You will get the dedicated medal first then you can get the die-hard, the fanatic is really hard to get though but of course you can get it if you don't stop!.
