Our editor will do it's best with any size image that you throw at it, but for the most control, uploading an image that is square and at least 500px by 500px will give you the most control and highest quality results.
When editing images to optimally fit...
- Do NOT use Microsoft Word or Paint. If you don't have a photo editing software like Photoshop, use Pixlr, a free online photo editor
- Resize the canvas of your image rather than the image itself to preserve image quality. Here's a tutorial on how to adjust the canvas size using Pixlr: http://screencast.com/t/KRxrHpGd4q/