I think the established coins would be those like bitcoin, dash, litecoin, etherium, and a few others that run on the X11, script, sha256 and quark algos
Those are all being mined heavily
So I think what the idea would be is to mine the smaller, less mined coins and hope that you can choose the ones that pick up in value in the near future
Ideally you need to purchase an asic batch 1. Before too many are released (I'm looking at you BitMain)
Watch for brand new coins and set up the PC to mine at least ten of these every month. Download the wallet for the coin on the PC, mine when it is brand new for a couple days and you will get a good bunch of coins since the diff is so low in the beginning.