VS Code
Command/Ctrl + Shift + P
Command + Option + ↑/↓
File → Auto-save
Saves a modified file upon losing focus.
Open the Command Palette, type shell command, and run the "Shell Command: Install 'code' command in PATH".
code <dir> launches VSCode with that directory.
code -r <file> opens the file in VSCode. If the file's directory is already open in a VSCode session then the file opens there. Otherwise in your most recent VSCode session.
MacOS: Command + P
Windows / Linux: Ctrl + P
Or you open Command Palette and delete the >, which switches it to "Quick Open" mode for files.