Are we restricted to legal methods (and in which jurisdiction)?
Crowdfunding - GoFundMe and Kickstarter
Live Streaming - Twitch, adult (if you're into that)
Online markets - stock/day trading, auctions
Cryptocurrency mining
Bing points - (shameless referral link -> https://www.bing.com/explore/rewards?PUBL=REFERAFRIEND&CREA=... ) yes, I earn enough points every few weeks to redeem for Amazon gift cards.
AdSense - putting ads on your website. I earn ~400/yr on my different websites, which more than pays for the hosting and domain registration fees.