One of my favorite add-ins for Visual Studio has been JetBrains ReSharper for many years already. It is paid, but in my opinion it's surely worth the money and does contribute to writing better code and learning more about programming efficiently. I know there's a lot of magic in this tool that I don't know about yet. One of my customers recently pointed out one of those hidden features which has directly made it to my personal top 5 greatest ReSharper features. What it does is enable real-time decompilation of 3rd party code, including the Microsoft standard ones. So no longer will you need tools like ILSpy to dig into the dungeons of the SharePoint framework to find out how an object is being handled, you can simply use the standard Go to Definition (F12) option to go right to the sourcecode of that particular SharePoint class. A-w-e-s-o-m-e! :)
Thanks to Kjetil Gullen for sharing this magic!