if you think there is a good chance that one of these coins is a scam, it probably is. First thing to notice is if what the project is promising sounds "too good to be true", if that is the case, it's more likely a scam. If the business model of the coin (read the whitepaper!) sounds like it's something genuine and it makes sense to you, then you should check whether that project is backed by a good team as well. If they have experience in the sector in which they try to develop, if they have the financial means to pay their obligations and if the idea is any good to start with. Most of these questions can be answered in the social media channels of these projects, so it's a good idea to simply join on and ask the founds right away. If the communication is good and what they answer makes sense to you, then it's more likely that the project is serious, which means you're more likely to profit out of it.