Taking about crypto related investment i think staking , lending and masternodes are good options. For staking if you see
https://www.binance.com/en/staking page alogrand is about 16-20% at the moment similarly kava 14-16%.
For masternodes its one time work to buy vps or setup on your own and let the rewards come ..pretty much auto-pilot. Apart from affiliate marketing you can use your bitcointalk profile to get project/bounties and outsource maybe if that is allowed i am not sure though. Or maybe create a udemy course
Apart from online work you can buy apartment and list it on airbnb.. similarly you can put your car for rent etc.