Choose the correct answer. Gerund or infinitive?

1. I'm not keen on doing voluntary work.
2. Mario Balotelli is a footballer who is famous for wearing diamong earrings.
3. Finn was lucky to be selected for the final of the competition.
4. Artists often need to find inspiration outside, looking at nature.
5. After getting the fifth tattoo on my arm, I decided that it was enough.
6. Girls in the Kayan Lahwi tribe wear neck rings to show their cultural identity.