Earning money with bitcoin is just earning bitcoin since bitcoin is money. Anyways you can try trading if you like big profit and a challenge or you can check services too to see if you can do something for people
Trading is obviously one of the best methods of earning bitcoins but for that someone would probably need a good enough capital and some knowledge as well, though knowledge can be gained by reading but the capital is not something that you can get from anywhere, so trading is not for those who are new to bitcoin and just starting with it or maybe it can be for them if they can buy bitcoins.
it is the best method to be honest, i think it can earn you really easy money over time if you do it often