Honestly speaking there is no perfect way of finding a legit ICO because many times we have seen scams where the team behind the project was active on social media and amount raised was transparent but still the project got scammed. So you truly can't locate faults in the project but still you can try by reading the whitepaper or investigating about the past work of the project or analyze the utility they are offering and future of the ICO and you can have a legit one in your hand.