A great start when architecting a workload is the Azure reference architectures page: https://docs.microsoft.com/en-us/azure/architecture/browse/.
Your workloads are special, but it is very unlikely you are doing something never seen before, so check and see whether one of these can give you a jump-start toward your end architecture.
So, how do you perform architecture reviews?
The intent behind architecture reviews of reliability, cost management, operational excellence, performance efficiency, and security is to ensure architecture is unified, non-functional requirements are considered and implemented, and everyone is on the same page.
You will need to plan the cadence, which, depending on the speed and the volume of change in your organization, might be from every two weeks to every quarter. Err on the side of two weeks; you can always cancel the review if there are no changes.
Here is an example of a quarterly plan from one SRE team (as an example...