Shake it out. Every time you make your bed, give your comforter a good shake to loosen up any feathers that have settled in the corners. This will help keep it looking its best.
Use a tennis ball. If your comforter is really uneven, you can try using a tennis ball to help redistribute the feathers. Place two or three tennis balls in a dryer along with your comforter and dry on low heat for 10-15 minutes. The tennis balls will bounce around and knock the feathers loose, helping to even out the comforter.
Redistribute the feathers by hand. If you don't have a tennis ball, you can also redistribute the feathers by hand. Start by separating the comforter into two or three sections. Then, use your hands to gently move the feathers from the corners to the center of each section. Repeat this process until the feathers are evenly distributed.