It's simple really: if you won't even research the ICO properly (and that doesn't mean just "hearing good things about it from others"), then you should wait a while until after the ICO, to see if it's still worth investing in it.

Also, think about it from this perspective at least: the more hyped an ICO, the more likely it is that everyone will want to sell on day one. So if you want to invest in a coin that has the potential to still grow a lot, then don't chase hyped ICOs.