I think the best way to get into Altcoins is bounty hunting as we might get some potential tokens in the future but if you are referring to coins that are already on the market then try to look for coins listed as top 15 or even 20 for safety. My previous investments are poured into Dash, Litecoin, Ethereum, SXDT and IOSToken. I actually  earn pretty good profits from those coins I've mentioned before the market turns red.