First of all I splurged and bought the giant sized plate - 12" x 14". At first I was too overwhelmed to try it. I thought I had to work big. But as it turns out I do not. In fact I am working smaller than ever. The large plate gives me the freedom to do that without the confining space of the smaller ones.
I have room to ink more than I need and that way I am better able to compose and design my pieces with the added space. If you can afford it, I would suggest buying the larger plate. I think you will agree that you will feel freer.
I decide which part of the design I like and place my mat board over the area. I have added tape to the corners where I want to line the paper up every time. The tape matches the corners of the paper. This board is for the 9" x 12" paper. I have a different board for each size of paper.