Capping costs on GCP for many projects with a budget for many months - Tracking billing info for project.
Getting Started on GCP: Billing Accounts - Understand Billing Accounts on Google Cloud Platform.
Whitepaper: The guide to financial governance in the cloud - Importance of financial governance controls and the role these controls play in increasing the predictability of cloud costs.
Predict your future costs with Google Cloud Billing cost forecast - Availability of a new cost forecast feature for Google Cloud Billing to know costs trends and how much you are projected to spend.
Breaking down Google Cloud costs by location (or anything else!) - Article explains tools to use to label GCP resources so their use can be collected and visualised.
Google Cloud Platform Cross Org Billing - How to use same billing account across multiple organizations.