How to store git HTTPS passwords / credentials permanently so you only have to enter them once

Problem:

Every time you clone a git repository or push/pull, you have to enter a username and a password (e.g. for GitHub or your GitLab installation).
Instead, you want git to store the password so you only have to enter it once.

Solution:

Configure the git credential helper to use a plaintext store instead of the default cache:

git config --global credential.helper store

NOTE: This approach will store your passwords in a plaintext file, so depending on your setup this might be a security risk.