Wells...you need a program for it. I used one called Draw Plus which I got free with a computer magazine I think you can do animation on Photoshop too....
I THINK this is the drawplus thing I have if u wanna download it --> [link]
Anywhos, just get a template of a stamp which u can do by typing stamp into the search thingy and then paste it into whatever program u are using and you should be able to make one from there...I hope that made sense If u have any other questions on it please ask
If you have a subscription you can put this stamp in your journal by copying the thumb and pasting it there!
If anyone else wants to make anymore they are always welcome!