Unless you have skills that you can bring to the table then you might be able to exchange that for some bitcoin.
Earning bitcoin is no more different then earning dollars or euro's. You have to provide a legit and good service to users. In return you will get paid for your effort/service.
This means you have to conduct your business with honor, where your client is the center of your operation. The service at hand can be anything, because bitcoiners are into anything.
Sell tweets, write articles, build faucets, the possibilities are very large and so is your profit.