Needing to add third party repositories - looking for suggestions on the safest way to do so (Debian 12).

[Priest_Apostate]

Just reinstalled Debian 12 (Bookworm) to clean up issues with my repos directory causing issues with updates. While I think I now have my /etc/apt/sources.list file correctly configured, I need to install Powershell, Terraform, and Visual Studio Code (this one is to work on Python 3 projects). As quite a few of these programs have third party repositories, I would like to know the safest way to do so (so that it won't end up requiring another reinstall).