The fastes ways are illegal. It is something as stealing and hacking. But that are not ways you are asking about I guess. I would call my favorite way for making bitcoins fast it is commenting on the forum. When you reach the rank of hero capaigns pay you really good money for your comments and in you are active speaker and have great knowlages about bitcoins and crypto world - you can make bitcoin fast this way as well.
Yeah, but the signature campaign route isn't exactly *fast*. The Yobit campaign is relatively fast, but they are not open to newcomers anymore. As stated above, scamming is the quickest route. That's the answer to your question, but don't do it. Be honest lest Karma bite you in the ass.