It's something I find myself doing over and over and over.

Okay, but why are you adding a .gitignore entry to the .gitignore file?

I was looking @ https://stackoverflow.com/questions/767147/how-can-i-stop-gitignore-from-appearing-in-the-list-of-untracked-files and it seems like it is best practice to leave it out. However, I usually end up with a ton of junk files / cached stuff from my IDE.

Would it be better to add this instead?

# VS Code
.vscode
.vscode/*
!.vscode/settings.json
!.vscode/tasks.json
!.vscode/launch.json
!.vscode/extensions.json
*.code-workspace

As the top answer (with 900+ Upvotes) in your cited SO question states:

The .gitignore file should be in your repository, so it should indeed be added and committed in, as git status suggests. It has to be a part of the repository tree, so that changes to it can be merged and so on.

So adding itself to a .gitignore file makes no sense at all.
If you really want to ignore some files only locally, you should either put them in the .git/info/exclude file in your project, or place them into your global gitignore:
https://docs.github.com/en/free-pro-team@latest/github/using-git/ignoring-files#configuring-ignored-files-for-all-repositories-on-your-computer
(Thats what I do for stuff like OS-specific files, VSCode, Office temp files, archives and other things).

Sounds good.