You can choose whether you want a head start with a master file, or you want to build a scene all by yourself from scratch. If you choose the later, this is what you do:
- Go to Photoshop
- Create a New Document and give it the needed dimensions. The dimensions depend on your scene’s usage. For example, if you need a Facebook cover scene, you would choose something like 851 x 315 px.
- Choose Transparent background.
- Name you document.
- Click OK and save the document as PSD or TIFF file to continue working.