How To Make A Photo Frame Template

Hello folks, hope everyone is doing good. I come to you fine people for some help. I’m a long time buyer here with hopes of becoming a seller. I think I have found the area in which I wish to become a seller which is making photo frame templates. The problem is, I have no idea how to go about making them. I have some great ideas, I just need some help in getting started. If someone could make me tutorial, or point me in the direction of one, it would be greatly appreciated. I would like a tutorial that explains how to set up, from start to finish, a photo frame template, collage type. Here is a link of an example of what I’m talking about. I will be using my own custom shapes, so I just need the instructions on how to correctly arrange them and make them into smart objects. Any help in this area would be greatly appreciated. Thank you all in advance. Peace and God Bless. Mitch