Buy and HODL. This is considered to be the most common way of earning money from cryptocurrencies. Most investors buy coins such as Bitcoin, Litecoin, Ethereum, Ripple, and more and wait until their value rise.
I agree, if we don't have so much free time that we can do our own trading in cryptos it is best to just HODL. We can save excessive trading costs by just holding our coins through crisis. Crypto coins tend to move in cycles, so if we don't need the money at the moment we just sit out the bear market and wait for the rally.