On my opinion I think the best way to earn bitcoin is through joining on bounty signature campaign here in the forum. For me it is the best and safest way to earn bitcoins. On the other hand, you can earn Bitcoin the same way as earning fiat. So if you want to earn some Bitcoins without investing money into it then you could offer services and accept Bitcoin as payment. In addition, by investing time and effort only, bounties and signature campaigns are on the first seat. Now, I don't if there are still some people who wants to do this but, there is this thing where you're just going to answer some questions. But I also agree on your opinion that, if you wisely invest your time and effort you sure could come up with patterns in the industry on certain coins and use that to profit BTC.