There are some sections that don't count as much, HOWEVER- if you are making all-around the forum quality posts, then they are not fluff.
If you make this as a post in agreement to someone: Cool, I agree.
That is fluff. If you make this post in agreement to someone: Yes I agree with you on all points. I'm glad someone else out there has the same opinion Thank you for posting this!
Helping people in the help section, commenting and constructive criticism or praise in guides & how-to's, wishing people in the forum a Happy Birthday, welcoming people in the 'My Name is Joe', adding information into the charm forest, curio shop, Fairy finds, and other WW
forum areas are good places to make your non-fluff posts, as well as many others.
The forum is very large and there are LOADS of places to make your non-fluff posts. But the polls, roll-playing, naming shops, and contests I believe do not count towards your 50 posts, although you should still do those areas because they are fun!
Good luck on getting gifted!