The one thing that I'd make sure to do is to define the area they are to write in. You want to make sure there is enough of a boder around the blocks to sew them together when you are done. The other thing I heard of someone doing is to make a quilt the size you think you may need in a solid or tone on tone color and go ahead and quilt it so that you don't have to worry about the quilting distorting the names and then when the wedding is over the quilt is done too.