macOS Sierra Developer Preview 10.12 has been released on the mac app store to developers. A redemption code can be obtained from https://developer.apple.com/download/ after logging in with a developer ID to then download the installer.
To make a bootable usb format an 8 GB (or preferably 16GB) USB3 drive which should be called Untitled and formatted as Mac OS Extended (Journaled). The installer should be called Install 10.12 Developer Preview.app and should be in your Applications folder.
Run this in terminal and wait about 20 minutes:
sudo /Applications/Install\ 10.12\ Developer\ Preview.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ 10.12\ Developer\ Preview.app --nointeraction
Also, reverting core storage still works in Sierra.
If the installation creates a core storage logical volume you can revert it to get partitions back to normal by running these 2 commands in terminal.
diskutil cs list
and then
diskutil coreStorage revert lvUUID
where lvUUID is the last lvUUID reported by the previous Terminal command.
Then restart for everything to get back to normal after you have run these commands in Terminal.
This is good if you want the recovery partition to show up in the startup manager you get when booting up with the option key.
To make a bootable usb format an 8 GB (or preferably 16GB) USB3 drive which should be called Untitled and formatted as Mac OS Extended (Journaled). The installer should be called Install 10.12 Developer Preview.app and should be in your Applications folder.
Run this in terminal and wait about 20 minutes:
sudo /Applications/Install\ 10.12\ Developer\ Preview.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ 10.12\ Developer\ Preview.app --nointeraction
Also, reverting core storage still works in Sierra.
If the installation creates a core storage logical volume you can revert it to get partitions back to normal by running these 2 commands in terminal.
diskutil cs list
and then
diskutil coreStorage revert lvUUID
where lvUUID is the last lvUUID reported by the previous Terminal command.
Then restart for everything to get back to normal after you have run these commands in Terminal.
This is good if you want the recovery partition to show up in the startup manager you get when booting up with the option key.