Read whitepaper and research well of company where you are going to invest because many scams are done by this method. Check whether it is genuine or fake..
that's the basic rules.. In addition for me it will always good to know how to make technical and fundamental analysis so that you can get specific information what is the situation of the projects you want to invest.. Many projects delivering a good testament but they always ended into a scam , so we need to be smart enough before investing or whatsoever.