Conceptual Question: When Informing A Client On Future Outlooks For Their Portfolio, How Many High-Level Trends Should I Mention?

Practically speaking - there's generally a house view on the economy, capital market assumptions for the year, and the macro level environment that impacts your investment process. Then within that, there's outlooks/strategy perspectives on how you are allocated, positioned, favorable or unfavorable sectors, etc. You'll pull from all of that, based on the client, to help them understand what they biggest themes are. 

From a conceptual standpoint, the goal in my view is to create a simple message focused around 2 or 3 key themes over whatever the time period is. They should be things that are meaningful to that specific client's situation, and consider everything from their actual investment portfolio's holdings to any 'hot button' topics that stakeholders at that client may care about.