Depending on the pose you may find it easier to install a support wire into the form, as shown.

Notice the clothespin on the top wing support wire. This will hold one of the magnets in place until you can get the other magnet to attach.

This shows how you can get the desired cup in the lower half of the wing or secondary feather area. A light wire can be taped to the bottom of the underside strip and then is bent to the desired amount.

It's easy to re-adjust any feathers. Take a clothespin and clamp it on both strips to temporarily hold one end while you lift up the top strip to line up the feathers. Once in line, let go of the strip and it will fall back into place.

The tail can be done with a pair of strips straight across or you can use two small pairs as shown to get the feathers lined up. Do not be afraid to use support wires where needed if the strips tend to pull your bird around from the force of gravity. Support wires are more easily hammered into the form than pushed in by hand.