If I've created a collection of assets that I need for our corporate pages, how do I choose assets from that collection while I'm authoring pages in AEM? I only seem to be able to drag/drop from the usual tree structure and can't tap into my collections. 

FYI - your Part 2 slides link to the Part 5 slides (they related to MSM and not search/navigate).  The Day 2 slides are missing from the training.