Participated at pre ICO is more benefit than you invest your money at ICO, when you make investment at pre ICO you got much coin with lower price than you are joining for investing at ICO time.
I consider the specific coin in the clay market first does the coin fulfill my needs and be worth investing? well that's what I'm thinking
Good point we will have to remain careful about power and value of coin in market, for this do all standard things like searching on YouTube google to invest in good coin, and promising one, apart from it we should consider all previous record of that coin related to the price, as if you are investing in a coin the price is falling and falling only since few years then its not worth profit, if price kept on changing with time then its good one I guess.