PART ONE:
Magic Wand Selection and Composite

  Open the 2 images, giraffe.jpg and backdrop.jpg and composite the giraffe image onto the backdrop image by doing the following:
1. Select the Magic Wand tool and check the options. Make sure that the tolerance is set to 32 (this is the default setting, OK for now). Also make sure that the anti-aliasing and contiguous buttons are selected.
2.

Click in the sky area. Notice that some of the sky is not selected. Go to Select>Grow and and the Select>Similar. Now notice that virtually all of the sky has now been selected. (Note: With this method, however, some of the whiskers and main have been eliminated, we will talk about this later).

3. Now, go to Select>Inverse. This will reverse the selection to select the giraffe. I would put a small feather radius on this selection, 0.3 to 0.5.
4. Using the Move tool, drag the giraffe onto the backdrop image and position this new layer so that the neck of the giraffe is cropped on the lower left of the backdrop image.
5. Zoom in on the horns and the mane. Notice that there are some jaggy problems in the horns and the mane has inherited some sky color from the original image (called haloing).
6. To fix this, select your giraffe layer and click the F symbol in the bottom left corner of the layers palette.
 
 

This is the Layer Styles menu. Now, chose Inner Glow. We are about to fix most of the haloing effect.

7. When the Layer Styles palette comes up adjust the settings as follows:
In the Structure section:
Set the Blend Mode to Color.
Reduce the Opacity to 50%. You could use more, experiment.
Click on the Color Swatch. The Color Picker box will appear.
8. Next, if you slide your cursor over to the giraffe image, the cursor will turn into an Eyedropper. Click on the brown/orange part of the mane. This will select a color that will be more appropriate for the blue haloing effect.
9. In the Elements section:
Raise the Size to 40 pixels. Leave the rest alone for now.
10. Done Deal! SAVE your file.
I would try it again from scratch and play with various feather tolerances on the giraffe and see if you can include the whiskers this time.