BEST WAY TO MINE CRYPTOCURRENCIES?

The best way to mine would be to set up your own mining rigs. Some cryptocurrencies can be mined using ASIC hardware while others need you to use GPUs. So depending upon what coin you would want to mine, you need to buy the hardware accordingly.

If using your ASIC hardware becomes unprofitable for a particular coin, you could still use it to mine a different coin but of course every piece of hardware has a life ( typically 3–4 years I guess)