Template:VM Settings Easy Common
Easiest, but least secure option. (#more security)
For Qubes-Whonix, click on expand on the right.
Create a new VM.
Set sys-whonix as your VMs NetVM.
For Non-Qubes-Whonix, click on expand on the right.
Download and use the default Whonix-Gateway.
Set up a Whonix-Custom-Workstation.
There are currently two ways to set up a Whonix-Custom-Workstation. Either 1) manually create a VirtualBox VM (old, stable way); or 2) download and import Whonix-Custom-Workstation (experimental, testers-only).
If you want to manually create a VirtualBox VM (old, stable way), click on expand on the right.
Create a VirtualBox VM.
VirtualBox -> Machine -> New -> Next -> Enter Name (for example: myVM) -> Enter Operating System and Version -> Next -> define RAM -> Next -> create a new hdd (or not) -> Next -> disk format doesn't matter, VDI works fine however -> Next -> dynamically or fixed size is a matter of preference -> Next hdd size and location is a matter of preference -> Next -> Create
Switch VirtualBox VM settings.
Choose the newly created VM (for example: myVM) -> Settings -> System -> Motherboard -> Hardware Clock in UTC
System -> Motherboard -> Pointing Device -> PS/2 Mouse (required so that USB controller may be disabled)
System -> Processor -> Enable PAE/NX if available
Network -> Adapter 1 -> attached to Internal Network (Important!)
Network -> Adapter 1 -> Name (of Internal Network) (Important!):
(Note: It's Whonix, not whonix. Case sensitive. Capital W.)
USB -> uncheck Enable USB controller
If you want to download and import Whonix-Custom-Workstation template (experimental, testers-only), click on expand on the right.
The idea behind this method is, that you do not have to manually create a new virtual machine. To simplify the process, you can just download and import a so called Whonix-Custom-Workstation. This has the advantage, that you have all security settings for the virtual machine, you cannot forget to apply any settings and it is easier.
Latest Whonix-Custom-Workstation Version: 9
Don't wonder, the version number for Whonix-Gateway and Whonix-Default/Download-Version might be higher than the version for Whonix-Custom-Workstation. This is normal. 
Rename the virtual machine to something else. (VirtualBox -> Right click on VM -> Settings -> Name) (For example: myVM)
Please report in the forums if you used this and how it worked for you.
Start VM and Install Operating System.
Start the newly created VM (for example: myVM).
Insert the installation dvd.
You don't have to install updates while installing. You can do that right after installing, after the network has been set up.
- This is because redistributing a newer Whonix-Custom-Workstation is only worth the effort, if the settings for the virtual machine have changed. For example, these have not changed between Whonix 9 and Whonix 9.2. So Whonix-Custom-Workstation version 9 is up to date enough (because it comes with an empty virtual hard drive, so no software could be outdated).
- It would not be necessary to rename the VM at this point, but if users are told to rename it now, and later import another Whonix-Custom-Workstation, they won't run into any naming conflicts due to another VM using that name.