1. Find out what kind of information that is wanted from the model and what kind of data you have available that could help with this. 1b) And note down other requirements for the solution.
2. Find out how to formulated the information needs in terms of a well-understood and well-researched problem.
3. Find out what the current best performant and well-understood solutions are for this problem. Usually through a literature search.
4. Choose a few candidates, and rank them wrt your particular requirements.
5. Test out 1-3 of them
This is a business-needs-first, top-down type method. Prior knowledge of the details of a lot of algorithms not needed. Ability to understand terminology and quickly identify relevant material/papers critical. A good overview of common problem formulations and methods will build over time, and speeds things up immensely.