To make your own all you need is a frame with some extra room on the mat. I’ve seen them plain or you can do what I did and just remove the cheesy phrase or unrelated word on an inexpensive one you find. Most are stuck on with something very easy to rub off. Before I bought this one i opened up the frame too make sure that I could remove the “dog” lettering.
Next I cut out a decorative word out of vinyl on my Cricut cutting machine. I just searched in Cricut Craft Room and found this sweet design.