Try trading. More profitable than all other business, you don't suffer any bounty manager's affectation, or look for a friend to suggest a referal code. You need to do is collect information thoroughly and apply them on charts. There is no delay in payment or anything else.
Unless of course the exchange your trading with suddenly disappears, then you're screwed. 
Everyone talks about blogging, commerce, using referral systems, bounty, campaign signatures, streaming, selling courses, offering their services in gaming, camwhore. But there are other not so known ways to generate/earn cryptos?
As for OP question, one way to earn/generate crypto is just simply by viewing ads. Brave browser offers BAT tokens in exchange for viewing ads within their browser. Content creators and publishers also get a chance to earn BAT tokens by sharing their referral links on their social media channels.See their website here: https://brave.com/
You can also offer various services, not only in gaming but also in the technical field such as helping startups build their platform, designing websites; even social media management is a thing in crypto-world now. Some startup companies offer payments in cryptocurrencies rather than the traditional fiat.