I am not infrequently asked (especially by transactional lawyers) about the way to brief a barrister.
The NSW Bar Association has published a tool-kit which is aimed at in-house counsel preparing a direct access brief, but it also applies equally to solicitors who do not frequently practice in litigation.
The tool-kit offers a useful guide (but might be regarded as too prescriptive for more simple requests for advice), but from my perspective the best advice is to liaise with the barrister’s clerk and the barrister about the form of the brief.