Plan, plan, plan
Anything can be animated, but I would just suggest that you plan it out before, so you save a lot of time. No matter how short the story, a quick storyboard is a huge help. Work out what you will need, and do it on separate layers first, so you don’t have to keep going into your image.
Creating assets the right size will be useful; making anything too big will just slow your programmes down. You won’t need to make anything much bigger than HD 1920px x 1080px, and a resolution of 72dpi, in comparison to 300dpi in print.
The easiest way to render a GIF (and the only way I do it) is by taking a video into Photoshop, pressing ‘export’, then ‘save to web’, choose GIF, click ‘looping options’ to ‘forever’ and save.
Finally, check out Geoffory de Crécy’s loops. This is the perfect example of a story being told with one looping scene!