Step 1

Open a new canvas, 72dpi, white background, 400 x 600 pixels.  Create a new layer fill with black.  Create another new layer (call it outline) and draw in your basic shape.  It does not have to be 'perfect' as there is room for correction later.  You can see from the example here, my shape is far from being a good sketch.

Step 2

Using your magic wand click on the top section of the wing.  Go to Select/Modify/Expand by 5 pixels. 

Step 3

We now want to fill this section with a gradient.  In this example set foreground color to 73D198 and background color to 4A6D4E (you can experiment with different colors).

Step 4

Go to Filter/Texture/Craquelure and enter the following settings.Crack Spacing 6, Depth 3, Brightness 6.

Step 5

Go to Select/Modify/Contract and enter a value between 15 and 20.  Create a new layer and fill the inner area of the wing with black.

Step 6

Go to Filter/Blur/Gaussian Blur and enter a value between 35 and 40. Ctrl+Click on the original wing pattern layer.  Go to Select/Inverse and hit delete key to remove any excess shadowing.

Step 7

Turn of the eye for all layers except the pattern section and shadow layer for the wing.  Merge visible and turn eyes back on.  Create a new layer above the 'outline' layer and repeat the steps above for each section of the wing.

This takes time as it involves switching between gradient color and shadow color.  You need to use the magic wand on the outline layer, but to fill with gradient make sure you have created a new layer.  Similarly when doing the shadow for each section - create a new layer.

Once all sections of the wing are done, turn off the eye on your outline layer.  You should have something like this.

Step 8

You can see that we have some gaps.  Try to arrange the segments to eliminate this.  Don't worry if you still have some gaps, we will fix this shortly.

Once satisfied with you arrangement, turn off the background and black fill layers and merge visible so that your wing segments can be manipulated as a whole.  You may want to rotate the wing for a better position.

If you still have some gaps you are not happy with, create a layer below your wing layer, and paint these out using the darker green color.  Once satisfied, merge the wing with this painted layer.

Step 9

Create a new layer.  Using the lighter shade of green (73D198) we will now begin to draw the spines on the wings.  Follow the line of where the segments meet.  Use your eraser to thin out the end of the spines.

Step 10

Go to Filer/Noise/Add Noise and set value at 25, Gaussian, monochromatic checked.

Step 11

Double click on the spine layer to bring up layer styles. Check Bevel & Emboss (default) and check drop shadow at 75%.  Change spine layer to hard light mode.

If you are unhappy with any area of the wing, in terms of shape, use your eraser to define shape in line with spines. (Remember, it does not have to be perfect, dragons usually have wings that have taken a beating from time to time, lol)

You should have an image similar to this.

You can merge the wing and spines, and copy and flip horizontally to get a pair of wings.  Once you have a dragon, arrange and angle as appropriate.  There is an example below.

These wings were made reversing the gradient colors (i.e. dark color as foreground, light as background)