MORE WING HEADCANONS!  
Cadence- Her wings are based off the River hawk or Osprey, mostly because they have really beautiful wings that are long and narrow. Cadence’s body is long and slender like and Ospreys is so I thought it to be a good match. Her wings also have long and very spread apart wing slots giving them a pointed look. Her wings look altogether different from the other princesses due to their slender style.  
Luna- Her wings are like an owls wings, more specifically the Great Horned owl. Her feather and wing type allow her to fly silently, this makes it easier for her not to disturb her sleeping subjects at night and when entering dreams. Her feathers are decorated with glittering stars and constellations that match the night sky and change as the night turns to dawn. She also has a bendable claw on each wing that matches the color of her plumage. She is the only princess with clawed wings  
Celestia- Celestia has four wings total, two primary wings that sit high on her back close to her shoulder blades and two secondary wings that connect near her mid back. Her secondary wings are the same size as twilight’s wings. Celestia is the only pony to have more than two wings and each are Bald Eagle like. Her wings are incredibly powerful but lack in speed, she makes up for it though, with endurance as her wings are perfect for long term soaring.  
(hope its not super silly for Celestia to have four wings I just think it would be hella cool and makes her more god like. idk i might scrap it)