For the idea you haven't made yet.
A photo you've kept for years. A place you miss. A joke that needs too much explaining. Start there.
Give "a cat" a little more to go on
The sleepy black cat on your favourite chair is already a better starting point. Six prompts to borrow, and a few ways to make them feel like yours.
Keep that one good photo
If the picture is already right, upload it and see it on a case. Your original photo stays the artwork.
See where someone else started
Browse designs made in the studio. Pick one to put on your case, or remix it and follow a different idea.
Try a name on a case
A name, a date or three words nobody else will understand. Try their position and download a mockup. For an order, add the lettering in an image editor and upload the finished picture.