Who needs a bootable setup usb stick with an operating system inside these days? Well, maybe you do :) ! macOS Sierra is the latest OS from Apple. If you own an older Mac and want to run Sierra then a bootable setup usb stick might suit you needs. Read on and remember: you try the following at your own risk!
When preparing macOS Sierra usb stick you can choose between a GUI and CLI (Command Line Interface). It's up to you which one you choose.
First off, open App Store and download macOS Sierra. It's free. When download has completed DON'T run the installer. That would install macOS Sierra on your HD or SSD. It's the usb setup stick we are after. Close the Installer window.
Next, download and run MacDaddy's Install Disk Creator. Find an 8 GB usb stick and place it in your Mac. Click Select the OS X installer. Then navigate to folder /Applications and find Install macOS Sierra.app. Click Create Installer and type in root's password. When done eject the usb stick and place in in your Mac again. Edit: I had to use Disk Tool to erase the data on usb stick (Mac OS Extended (Journaled) -formatted). Ok, that was the GUI part of the story. Let's move on!
One more thing. You need to know the name of your usb stick. In the example below the name is Untitled. And make sure your usb stick is formatted the Mac way (Mac OS Extended (Journaled) -formatted). And eject/place usb stick to make it work.
sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ macOS\ Sierra.app --nointeraction