In my years of experience with bitcoin there is only one effective way to avoid scammers. In joining ICO even if you do your research you will not know that they are scammers until the ICO is over. Even if how many preparations we do or make in the end we still end up being a victim to scammers. The best way to avoid scammers is to no invest your bitcoins. Just hold it in your wallet and hold it for a long time and when the price is right you can sell them and you will have a good profit.
That sure is a good conservative approach and I know many people who do the same thing.
But I guess anyone investing in ICOs is anyways signing up for higher level of risk vs award phenomena. The ROI on ICO investments (when done right) could be nice. Though, I see 90% of the ICOs that even 'experts' review / promote / bank upon are a loss deal... but the ones that made money... covered those losses many times over (or maybe they just got lucky).