One of the major advantages of creating window decorations of your own more than purchasing them is that you are able to personalize them. For instance, if you want to add a family message under a Christmas hanging or create several custom window clings that sit beside each other, there are a number of project ideas you can consider. If you have the design of something like a Christmas decoration in mind, you will want to look online.
The best place to start for this is Google Images. Type ‘Christmas decorations’ and you will see hundreds of relevant images. You will need to look at decorations that have a white background instead of pictures that have backgrounds of rooms. Your image should be large enough to create your window decoration. You may limit your Google Image search to medium, large or small.