Instructions:

Version 1:
1) Draw the blue lines as shown in page 2.
2) Draw lines similar to the green lines. The length and angles of the lines will show how big your wings would generally be.
3) Draw the feathers. Start from the left and bottommost point to the right and topmost point. Start with small feathers in increasing sizes. Do this 3 or more times (these will show the layers of your feathers.
4) Color and do optional shading and you're done!

Version 2:
1) Draw an S similar to as shown in page 6. The size will depend on how big you want your wing to be. The 'curviness' of the S would also depend on how you want your wing to be structured.
2) Similar to Ver. 1, pg. 3, draw lines similar to the yellow lines. The length and angles of the lines will show the size of your wings.
3) Draw the feathers. Unlike Ver. 1, pg. 4, you only draw one (1) layer of feathers. Make sure you follow the curve of your S and the other reference lines.
4) Color and do optional shading and you're done!