While working on the basic shapes of the Captain America Shield. I started with the flat colors, and went with basic shapes. Then I added Gradient Maps on Adobe Photoshop (Note: Adobe Illustrator's Gradients looked better.
Captain America Shield with Horizontal Gleam
Captain America's Shield with Inner Shadow with Brush Metal textures.
Captain America's Shield with Inner Shadow
Captain America's Shield with the Diagonal Gleam and Details
Captain America's Shield with the Radial Gleams
Captain America Shield with Metal Texture and Horizontal Gleam
Captain America's Shield with the Diagonal Gleam and Details
Captain America's Shield
Radial gleams
Captain America's Shield
(Flat Base Colors)
Captain America's Shield
Radial Gleam with a diagonal render