Protect Your Hands
Before clipping wings of your bird make sure your hands are safe from sharp nails of the birds. The protection of hands is also essential as you may slip the scissors by sudden movement of the bird during the clipping process and it injures your hand. You can either wrap a towel around your hand or use gloves while clipping the wings.
Catch the bird from bottom, just under the wings, and hold it tightly. While holding the bird, spread one wing on the hand that is protected by towel or gloves. Stretch the wing out the way the bird does just before flying. Then gradually cut the wings as much as you want with one hand, while holding the bird with the other. Make sure the bird does not move, as the movement can cause misplacement of the scissor and it can cut through wings at the wrong place.
Clipping Feathers on Both Sides
Make sure you clip feathers on the wings on both sides, equally. The clipping should be deep enough that the bird cannot fly but not too deep that it injures feathers' roots. The damage to roots may cause stoppage of feathers growth permanently. This will affect the bird's movement completely, and might also affect its health. Also, both feathers should be equal in length after clipping. After clipping the wings, leave the bird to move freely or cage it for while and feed it with food.