Unfortunately, as with Plots, the documentation is lacking. The basic tutorial does a good job introducing the aspects of the package at a high level, but the fact that some parts of the documentation uses functions/structs that don't have docstrings in examples makes it very hard to build on the examples in these cases.
I get it, I can do anything with Makie, and most things that I want to do work amazingly. But my code for a single figure can get huge because it's all so low level. See, for example, the Legend documentation[1].
[1]: https://docs.makie.org/stable/examples/blocks/legend/index.h...