There are two basic steps to making a DIY centerpiece from a cardboard box. First, you'll need to design the box itself, and second, you will need to decide what elements to put on display. Apply adhesive to the inside of the box, and tuck the excess fabric running over the top into it. This method also allows you to use real seasonal flowers in the centerpiece. Make your own DIY artificial mum flower centerpiece decor to add some fall colors to your table without having to take care of real blooms.