There is a section of code where I adjust some important constants frequently (for chunk, buffer sizes, and other vars that are constrained at compile time for now). In this section I have a commented area for quick todos and reminders, for when they are too trivial to add to Trello or I dont want to forget them.
For other details on my work environment:
I have 4 monitors - 3 primary ones to code on, and a forth to run the game on, fullscreen if needed (i.e. for recording). I use Sublime Text by habit, even though I compile in Visual Studio. I also have a bunch of batch scripts to automate C++ stuff I don't want to deal with (LZZ for automatic header generation is crucial for my sanity).
I also have several apps running in windows to reconfigure how the desktop works, allowing desktop switching and other stuff (I'm on Windows 7 right now). I used to program on a Mac, so I actually changed my keyboard to be more mac-like (switched the control and alt keys on my keyboard and reprogrammed them in the registry - hehe).