I was wondering how can I make my own image layers?

Load the 0_New image layer.
Then look for the Diffuse and Opacity thumbnails in the Modify Panel.
Select the Diffuse then click the Launch button--this will send the image to your image editor. (Note that the path to your image editor must already be entered into iClone's Settings.)

If you replace the Diffuse texture with your alpha PNG you will not need to repeat this process for the Opacity channel because that is extracted automatically.

In iClone 5, the act of saving the edited texture is monitored by iClone and the image layer will be instantly updated.

For iClone 4, you can accomplish this by clicking the Update button.

General Picture - animating now to life itself(tm)
Member of Content Wizards

Thanks!