Major Nelson announced today that Microsoft has added a new, custom Photoshop template in order to make creating custom backgrounds easier on the Xbox One.
In case you wanted to update your background with the NXOE, you can download the new file which is only 7MB in size and get right on editing and cropping. When you're done, you are also able to share the file for others to download and use as well. It's a PC download file so you'll need a photoshop software program in order to edit. Just like now, when you're complete simply load the usb into your Xbox One and head to the "My Home Xbox" section in your setting and select the background. You'll then be able to choose custom image and upload from the USB drive with your image selected.
The file is live now and able to be downloaded immediately. You can get it here if you're interested.