Du add content to clubs: images, videos, Artikel etc. You're also active in general there, answering Fragen and commenting on things. The Mehr people who Fan your stuff, and the Mehr Kommentare your stuff gets, the faster Du ought to get a medal.
The system is a bit Zufällig though: some people get Medaillen for a small amount of stuff, while others take longer. People sometimes get Medaillen in Clubs where they've been less active than the Clubs where they've contributed more.
It takes a while, so Du really have to be patient. It took me about a Jahr of being active here to get my first medal. It's better to just contribute for the sake of contributing, and just let the Medaillen happen.