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You can just organize a contest for fun. So if you think you will enjoy a sports betting contest where people need to predict who wins a soccer match, then you should do that.

Or you can organize a contest where people need to do something that you really like. For example of you like photography, it should be some kind of photo contest.

I myself would try to organize something where people need to help newbies, show me some great number/financial analysis or for the biggest newbie engager on Steemit (I would use @abh12345 curation league for this last one)