Think about the story you want to tell. What kind of setting would it need? Make a list of ideas for your background design. Remember, there are no wrong answers!
Choose your best idea and make a rough sketch of it on a piece of paper. Try to imagine how this would look as pixel art.
Go to Piskel website and click on 'Create Sprite' to start a new project.
Using your sketch as a guide, start creating your background in Piskel. Use the tools in the toolbar to draw pixels, change colors, erase mistakes, and more. Don't worry about getting it perfect, just have fun!
Once you're happy with your design, click on 'File' and then 'Save' to save your pixel art. Give it a name that reflects your story.