I add content to Wikipedia on topics which I have some expertise or experience. These include: photography, lawn bowls, the saxophone, ska music, and locations I have travelled to and have knowledge about.
Also, I edit careless spelling and gramatical errors.
I have made important contributions to the following pages: Henri Selmer Paris, Bowling Green, Narrandera, List of Saxophonists, Wake In Fright (movie), Independent Spirit Award for Best Film, Narrandera Shire.
I generally do not have a lot of time to contribute to Wikipedia.