You should consider the whitepaper too,read the whole whitepaper,join telegram and ask the developers if you have any questions it shouldnt be a business minded whitepaper. Look for the product/services that this ICO has to offer,if there is none i wont join. Check the founder's and developer's background,are they capable? The roadmap must be clear ,short and long term goals are needed. Lastly community's feedback to the project,if you received positive feedbacks join!