Should I choose X or Y cloud vendor?
How does a database technology A compare to a database technology B?
Why would I choose integration toolkit M while N is half the price?
Should I recommend buy or build?
So on and so forth...

Very tough questions to answer, especially if you don't know where the business is heading.

I found this brilliant scene from "Alice In Wonderland" as a reminder for myself:
Alice: Would you tell me, please, which way I ought to go from here?
Cat: That depends a good deal on where you want to get to.

Figure out what business objectives your architecture should solve. Identify prioritized use cases.

And technology selection becomes somewhat simpler.