Do both. Do not put all your money in ICOs and altcoins. Have a balanced portfolio - invest a part in bitcoin/ethereum, another part in top ten altcoins like OMG and the rest in promising ICOs. This is what I recommend. With ICOs do the research, read, follow, monitor. Do not invest based on marketing hype - pages of forums written by paid people, advisors for the marketing sake, etc.
In the future I'm gonna make money also doing both but I think I'm gonna need experience because as a trader it's not guaranteed you'll be able to get according to the way you want to get. As of now, joining signature bounty campaigns is the only option I have and I doubt if I can make my living by ICOs alone.