Maybe you already have heard of the browser CryptoTab with that you can earn bitcoin by mining on your phone or pc. But for that you have to let your phone or pc run all the time.
With my method you don’t have to let anything run. There is another app from the CryptoTab team called CTFarm.
There you can buy a hashrate with crypto and no matter how much you pay in the end it will always pay you more than you invested. 
For example I started with 15$ investment in Tron and bought 30H/s for 3 months. In the end after the 3 months I have made nearly 20$.
Of course this is not much but just for doing nothing it’s decent I think. And if you buy more hashrate you earn more it’s your decision.
If you also want to earn passive crypto income here is the Link:
https://ctpool.net/?aid=19920849