Look at what technology companies do to make their projects successful.   There are many, many things that need to be handled when developing a coin (project).  How do the tech companies handle these things?  They have several different departments which all need to work together to produce the best result.  They have marketers, and designers, developers, and testers, program managers, and business development folks.  There are real jobs for all these types in a well run coin.

Additionally, there are many "standard" things that others have mentioned, such as the tech, the team, the community, the white paper.... but there are also many, many things which will come up which you simply cannot predict because it is crypto.   How can you predict that the ambassador will want to force a tech decision, rushing out a wallet?   Or the treasurer deciding to run away with the team's coins?  Having come from the tech world into crypto ... things can get seriously crazy.   And not everyone is what they seem online. 

This also means that privacy is to be held in high value.   Even if you have absolutely nothing to hide, and aren't doing anything wrong, people do crazy things.  In the last couple months I have heard some seriously scary horror stories about peoples' lives being ruined by other people online.  It has changed my viewpoint on this dramatically.   So please be careful with your personally identifiable information.   Believe me when I say you won't in a million years be able to predict the craziness that may happen in a crypto project.

Good luck.