Well, the only trick I can give you (if it is a trick!)
is I felt that putting the Icord down about an inch was more stable then using just the edge if you know what I mean. Of course, you use the same yarn you used to sew it on with a yarn needle. And you can either put the Icord INSIDE the bag or OUTSIDE the bag. Strangely enough, mine looked better outisde the bag coz it flowed with the ummmm, I don't know, ok, it just looked better. inside would be good too, but if you use maybe not an inch, 1/2 inch. you know, more than the edge, you'll get better support.
Then you just sew with yarn all around... so it's a nice clean ATTACHMENT. Does this make sense!!!!