Along side some of the great advice given above I will add some of my own.
White PaperIt often takes a long time if you wanted to read it from cover to cover. Try to look for videos explaining the main concepts and summary on steeemit reddit etc.
This will give you a good primer for understanding the paper and reading it for main points. Now do some other research and come back to white paper for double checking.
GithubIt is easy to run ads and other campaigns but much harder to hire talented technies. Seeing Github activities is a great way to ascertain the quality of the project. There is a good article on this here:
https://steemit.com/cryptocurrency/@ashr/crypto-due-diligence-using-github-to-check-out-projectsBitcointalk!Looking at the types of content and user activities is a great way to ascertain the type of people you are investing in. Here to find out more.
https://steemit.com/altcoin/@ashr/crypto-due-diligence-2-using-bitcointalk-org-to-check-out-projectsBelief in foundersUltimately if you are investing in a project at such a early stage what is most important are the founders. And what you are looking for in these founders are 2 things: genius and integrity. When looking for genius, I would look at their technical,industrial or social competence. If someone is technical person stalk them on Linkedin, Github and various sources to see the level of complexity the person needed to overcome. If they are a industry expert, look at some of the successes they had before. Lastly, if are don't have either of these you need to look at the founder for their ability to unflinching move projects forward faster than any other human being out their. Looking at the kind of people they were able to attract to the project is a fantastic indicator of this. I think Brian Chesky of Airbnb is a great example of this.
Second most important factor is integrity. Is doesn't matter if the founders are extremely able if they are just going to run away with your money. This is even more difficult to make it tangible but I typically use the following. Does the project deliberately do things that are against their financial interest but good for integrity? e.g. Polkadot not doing pre-sale, Litecoin preventing premine,etc Or throughout their career has the founder done things that are difficult to do but need courage and integrity? If they are famous there maybe some good stories.
I found this to be practical enough for an average investor like me would love to hear other people's thoughts!