I've recently moved to Github (VS2017's built-in support) from Perforce for some individual projects. There is a feature in Perforce called "make writable" that allowed you to write to a file locally and then only submit it to the server by explicitly checking it out then submitting it.
This was used extensively for any binary files (.exe, etc) that only needed to be pushed very rarely but still needed to be written to.
Unfortunately from my limited experience with Github, it seems that all files are set to writable and are always marked as "changed", even exes. Is there a setting I can make or setup that allows Github to only mark a file as changed explicitly so I can't accidentally push an incomplete, broken, or debug .exe?
Updated answer: So, I forgot, if the file's tracked by Git at any point, then it gets a bit ugly. There are ways around this, but it isn't a single command to do this.
IF you want to do the .gitignore route, you can. But there's an added step (see below for first step). You have to, after each commit you do of the .exe file, run git rm --cached <filename>. This will remove the metadata around the file telling Git to track it. Once you do that, it won't show up anymore in the Changes list in the Visual Studio plugin (if you're on commandline it won't show up in git status). Then to add a file, you do what I mentioned below, which is to do the git add -f <filename>.
If instead, another way to do this, would be to run git update-index --assume-unchanged <filename>. This tells Git to ignore changes to the file. When you want to commit it, first run git update-index --no-assume-unchange <filename> and do your normal git add git commit workflow, then once you've committed it, run again the git update-index --assume-unchanged <filename> bit. It's messy, and honestly, I'd write a custom tool in VS to do this rather than relying on the built-in SCM tool in Visual Studio.
Original answer: Best way to do this (IMO, others will have their own opinion) is to add the files to your .gitignore. Then if/when you really want to commit them, do a git add -f <file> and then commit as normal.
Edit: Note that this is something everyone will have to do to avoid accidentally committing. A way around that is to commit your .gitignore as well so everyone has the same behavior.