I've just been adding the project references in Visual Studio, and Orchard's dynamic compilation seems to work out the binary dependencies, as long as the requisite modules are there of course. Unfortunately there's no way to force an installation of dependent
modules, and if they're not there the missing reference cause a compilation error.
I added recipes to the latest Media Garden releases but they still don't resolve the issue during install from gallery. That's a separate workitem:
So I think the best practice is to make the recipes readily available; they'll work if the user runs the recipe manually from the dashboard, and then recommend that as the quickest way to install your module.
You could try writing text in your gallery description, like "note: this module requires requires you to install [x] first". Unfortunately, people tend to install things without reading everything first, and the #1 issue I'm having reported is the installation