Depends really, do you want to look back in a year and see large gains, i.e. long-term hold. Or will you constantly trade? If the first I would say pick 2 coins that have good tech, My long terms are Deep Onion and Nav coin. The first because of its good marketing and active community. The latter because of the huge tech that it has along with a plan for Anonymous Dapps (or Valence as they call it), I expect this to be the anonymous Ethereum.
Now if you are going to trade regularly, ie every week and check your portfolio constantly I propose you pick 5 coins and split your investment along those lines. There are many good low market-cap coins like Oyster Pearl that look very promising even in the short run. Good luck and remember to diversify!