Hello! ;)
I also have some sort of "format" but all the details are way different (even when I write to the same person twice).

The format it follows is like this:
- Par. 1: I write about the celebrity and their work
- Par. 2: I write about myself (they want to get to know their fans!) and what's going on at the moment
- Par. 3: my conclusion where I also politely ask for a signed photo
As you can see, it changes every time as I put hard work into my letters and everyone is different so all the letters I send must be too.
Thanks & good luck collecting everyone!

Lizanne