Well obviously investing in ICOs is possibly the riskiest investments possible. Fortunately, we can allows do our due diligence and gather information before deciding.
I've been reserving a part of my portfolio for these kinds of riskier investments. Currently i'm investing in AppCoins (whose ICO just opened), Raiden, OmiseGo.

I always stay away from the more scammy looking ICOs such as Monetha and others...