There are many ways to design a unique matching sister tattoo, including hearts, flowers, or fish. However, the two most common designs are usually simple and similar. Whether you want a tattoo with a more intricate design or something simpler and more subtle, there are many options for both styles. Here are just a few ideas for a sister tattoo that’s sure to be a conversation starter. If you’re looking for a more original design, try a different shape or color.