I am just finishing up developing my first plugin, and wrote up my notes into a short tutorial for how to make your first plugin. For now it’s on my blog, but if there’s a better place to put it on this forum, happy to do that as well! You can find it here: https://cduvallet.github.io/posts/2018/03/qiime2-plugin
This post is intended to complement the QIIME 2 plugin development docs, and will probably make no sense if you haven’t also read that.
There’s also a related forum post that might be useful, especially as it gets updated.