Aside from the considerations one should make based on their personal financial situation, consideration of an investment in a coin usually goes through this process for me:
1. What's its utility?
2. Where is it at in its life cycle?
3. What's the team's experience?
4. Read the White Paper.
5. Wait a week and see if I'm still convinced.
For me i should consider the popularity of the coin and the structure. How many years since it created. And the last one is the history of the value in our market.