I've found a few links but they don't explain how this is done. I can debug using Xamarin Studio IDE but that IDE (no offense) is lame compared to Visual Studio 2012.
Using Visual Studio 2012, there appears to only be option to select an emulator to debug. So how do I get it to debug on my real device via USB (I already have USB Debugging = true)?
I'm using Visual Studio 2017 with a OnePlus.
In order get debugging working I did the following.
Side note: I have noticed that sometimes it also depends on the cable you use. If you still have no luck, perhaps try another cable.