The analog world is often very different from the digital world. We live in both, meaning planning a method of organizing “assets” will most likely be different for your digital life, especially how you manage your life outside of the one and zeroes you are looking at on your screen.
As a documentarian, managing content is a multifaceted task. Whether you manage your content from the micro or macro perspective, you can often apply the same approaches.
Consider content as blocks you are building with. Whether that block is a paragraph, a page, or a collection of pages, moving these blocks about should be done with the same ideals of knowing the structure you are using and following the same approach each time you move one of these blocks. Consistency allows you to understand where you can expect to find the information you seek, regardless of history.
Building these pieces of information into appropriate sizes and types of blocks also allows you to ensure that if you need to move a block, it retains all of its supporting information. This retained information can be in the form of sub-blocks or, perhaps, a collection of dynamic links to the supporting information. It mostly depends on the structure being used for the information.
Documentation that combines text and images should either include the images directly in the document or use a dynamic link to a stable repository of images. This repository can also exist as a sub-folder or block within a block of the document.
Moving to a collection of documents should retain this block and sub-block approach for each document. This will allow for the movement of the entire collection or the movement of a selection of documents within the collection, either within or without the overall collection.
This is much like the more straightforward principles of object-oriented programming (OOP), where you often use the same functional approach to various project parts and have individual functions manage smaller pieces of the overall application.
In short, decide your organizational structure, consider future requirements, and iterate on your approach. Organizing anything should always have a dynamic quality.