I’m currently working on an editor for my main project and decided to build up a small test environment in a Windows Forms project.
Now I want to share my researches and experiences I made. I also heared that a lot of people are trying to host a MonoGame game inside a Windows Forms application to create something like a level editor, but they don’t realy know where to start.
Further some of them dreamed about an updatable control, so it would be possible to create a GameTime based editor to - for example - create a particle effect editor or animation editor and seeing the results directly inside the editor window…
… welcome to the PenumbraPhysics.Editor! 
Click on the image to watch the YouTube video.
The editor is a compound of WindowsForms, MonoGame, FarseerPhysics(modified) and Penumbra(modified) to show how to setup a complex editor environment.
You will also find some samples inside the repo like a simple draw-control or a simple update-control. With them it should be possible to start learning and step by step creating a more complex editor. And yes, the PenumbraPhysics.Editor is not a complete editor solution. And it shouldn’t be! Because in the end you should be able to build your very own editor tools.
It’s possible to adjust editor object information from within a PropertyGrid; that’s why I also created some basic TypeConverters, UITypeEditors and HelperClasses from which it should be possible to build upon and extend editor functionality.
Please take a look at the official repo for a short tutorial and further description:
I hope this is helpful for people who are struggeling to develop their own editor solutions!
Cheers