Apple - What is the keyboard combination for the ⌘ symbol?

As the other answers mention, by default there is no easy way to enter this symbol. You could use a text substitution as well (none of the other answers so far mentioned that), but that’s another imperfect solution.

If you need this (or any other Unicode glyph) frequently and want to be able to type it on your keyboard, your best bet is to create a custom keyboard layout. That way, you can assign a keyboard shortcut of your choosing to the ⌘ symbol.

Using my custom QWERTY layout, for example, I can use ⌥+Shift+C to enter ⌘.

You can only do this if you choose "Unicode Hex Input" as your keyboard layout in System Preferences > Language & Text. Once you have done so:

Hold down alt and type 2 3 1 8

There is not a shortcut key, but the easiest way to use it is to favorite it in Character Viewer. If you don't see the Character Palette in your menu bar: , then go to System Preferences > Language & Text > Input Sources and make sure that the Keyboard & Character Viewer is on:

Then, in your menubar, click the character palette icon and choose "Show Character Palette" Search for "Place of Interest sign" or ⌘. Click on it and add it to your favorites:

Then when you need to type it, you can go to the Character Palette and click "Insert" or just drag it to where you want it.
Related: You can also copy all the symbols (⌃⌥⇧⌘⎋⏏⌫↑⇡↖⇞⇥ and more) from this meta post