A deal memo can help formalize your investment decision process.
It provides an artifact to reference years later when you go back to look at your portfolio outcomes, exemplifies your process and values as a VC, and provides a vehicle for bringing on co-investors (or offering the deal to your LPs if there is room in the round).
Hub provides a deal memo framework with template questions, ratings and attachments and links - this can be used for collaboration across your investment team, exported as PDF and shared as desired.

Check out the VC Lab article: Venture Capital Deal Memo