I made this t-shirt, using 2 t-shirts that I bought for less than $1 at Target.
I didn't take pictures of the process, but it's pretty simple, so I will give a description of the steps I took.
I kept one t-shirt in its original shape, and cut flower shapes out of the other one, using my BigShot. But you could do this easily cutting freehand flowers, since the shape of the flowers doesn't matter too much. I also cut flowers out of burgundy tulle.
I placed different sized flowers on top of one another, some of them layered with the tulle in between.
Then, I used my sewing machine to attach them to the t-shirt.
I am not so good at sewing fine pattern, so I just went back and forth, using a straight stitch. (See picture below.)