I guess it's time we started collecting tricks, tips, and shortcuts into one reference page, to help users in their quest to become Quartz Composer masters.
If you know of a tip, trick, or shortcut, or just a good idea, feel free to add it to this list.
Shortcuts
When opening the Preferences pane, holding the "option" key will give you access to advanced settings, including private patches, advanced tooltips, software GL, software CI, and DisableVBLSync.
When editing source code (In Javascript, GLSL, or CoreImage), using "shift-cmd-i" will open up a static inspector for just that patch. This inspector won't change as you select other patches.
cmd-up and cmd-down will exit and enter macro patches in the editor.
Holding down "option" while in the File menu will let you save a Flattened copy -- this will "flatten" your virtual patches into the composition, for easier distribution.
Caps-Lock "on" prevents Marcos being entered with a double-click. (Kind of a Gotcha)