To make a big bow for a Christmas tree, you will need the following materials: a length of wide ribbon, wire, scissors, and a hot glue gun. First, cut the ribbon into two equal lengths. Then, fold the ribbon into a loop and wrap the wire around the middle to secure it. Use the hot glue gun to attach the loops to the top of the tree. Finally, trim the ends of the ribbon to create a decorative bow. Enjoy your festive and beautiful Christmas tree!