The bride wants a buttercream 3 tier cake with raffia wrapped around for borders and a bird nest topper. I've dodged this look on rustic cakes until now. Do I just lay the raffia on the icing or should something go under it? And how do I connect it together in the back? Any advice you can give would be appreciated!
You should advise her that most raffia shreds really badly and that she will end up with threads of the stuff all over her cake. Your call if she accepts that fact whether you want your name associated with a cake with papery inedible bits all over it.
It looks nice on Pinterest, but I am of the belief that 99% of cakes on Pinterest are not real and not used for real events!!
Ayou could pipe a reasonable facsimile -- use a needle to make it look twisty -- use a real small tube to pipe the whispies and dust it with cocoa to make it look raffia-ish