Welcome from Ontario, Canada. If it is the one i am thinking of, I think I would just quilt it following the pattern or shape lines. You also could look at Mactavishing (intense quilting) inside some of the larger shapes. Put it up on your design wall and study it to see what appeals to you.
It also sometimes helps to have a large piece of clear tablecloth plastic big enough to lay over your wallhanging/quilt. You can audition different quilting designs on the plastic with a dry erase marker and the overlay (make sure it's marker side up) it on the wallhanging to see how it compliments the design.