How adorable! I have a pair of black suede pumps that I'm turning into these.
Q-tips/ thin paint brush
In a bowl, thin glue slightly with water. Starting at the point closest to the toe, apply glue with paint brush to the back of the feather and press down onto heel. Let dry before applying the next layer, working your way back to the heel. Once one side of the shoe is complete and dry, turn over to do the other. I found letting the feathers dry inbetween makes glueing the feathers on top much easier.