I have started a WinForms project a few weeks ago and as I did not really know what features I wanted, I just added them along the way. This now caused a horrible mess where
Don't throw in the towel on MVVM - it's valid for WinForms as well. Basically, if you use data-binding, you have to make a decision about what your objects will bind to. Often, especially for more complex UI, you dont want to bind directly to your domain objects, you want to build specialized classes (sometimes wrappers) that your UI can bind to which provide everything the view needs (the essence of MVVM) and the technique works just as well with Winforms.
A good series on WinForms Model-View-Presenter approach can be found at
The Build Your Own CAB Series Table of Contents