Choosing the right snomed codes

We’ve long had electronic forms for internal referrals but have recently rewritten and modernised the solution. I want to ensure snomed is used as much as possible. We can have an educated guess at which codes to us, supplemented by looking at certain FHIR resources and prior work around the internet, combined with any review by our clinical staff, time permitting.

How do others validate their choice of snomed code?

Can you describe the context in more detail? Are these codes to describe a document type, a question/field in a form, the set of valid answers, or something else?

Is it the forms/documents - the supporting information or the referral code - service request/rererral