Treasureit

I have this many t-shirts cut and ready to arrange, but for the life of me I can't get them to form an equal design. I have a couple shirts left that I can add, but they would be duplicates or they are not cotton. I also asked for some photos so I could add them in a couple blocks to even things out, but so far, haven't gotten any. What would you do?
ps. I do plan to add sashing around each block and then a border.