What are some ways to personalize my dad’s urn?

My family and I are stuck with the very difficult decision of choosing a cremation urn for my dear dad’s ashes. He was such an amazing husband and father, we really want something special for him. We’ve heard that we can order an urn online and have it personalized. The trouble is, we’ve got no idea how to make the urn unique. Can we ask for some ways that we could make the urn personal to my dad? We’re looking for original and creative tips that can reflect him as a person. Thanks so much.