Okay, I always put magnets in my bow tucks bags. But I haven't made one in 6 months so I forgot the sequence. I know you don't want to wait too late to put them on and I am thinking it might be before you sew the outside to the lining. You just have to measure carefully so you don't put them too high on the lining (I have done that and it is very hard to sew over a magnet). Also you have to allow for the 1/4 inch topstitching after you turn the lining to the inside of the bag. So find the center of the lining, allow about 1 inch from the top of the raw edge of the lining and attach the magnet with the washer on the pellon side. Does this make sense? When I get home today I will look at my pattern more carefully and if this is not the right instructions, I will let you know.