The obvious goal is to provide an answer to a research problem—preferably in a way that solves a client’s problem—and to do it efficiently.
Let’s assume you understand what the issue is. In finding an answer, you need to identify a rule that supports your conclusion. You’ll find that rule, one hopes, in both a governing text (a statute, say) and in caselaw—but perhaps you’ll have to settle for one or the other.
Then you must apply the rule to your client’s situation. Hence you must know the operative facts.
There’s more. You must locate all the exceptions to the applicable rule and show why they don’t apply to your client’s situation.
Then you must summarize everything relevant on page 1: the question, the answer, and the reason for that answer—ideally in a way that any intelligent reader might understand.
Obvious, you say? Pick a memo—any research memo in your office—and see whether it meets the standards articulated in the preceding paragraph. Test it.
You’ll have some fun with that, we think. Cheers.