Colouring tutorial
From this
to this 
Difficulty: medium
Program: Photoshop CS5
This tutorial will show you how to brighten up a dull image and add some nice textures. Best results are achieved with images with greens like the example - mountain landscape. I am going to show you more results in the end of the tutorial.
Step 1: Curves
Curves are great to fix image's brightness, contrast and colours at the same time. Make a new Curves adjustment layer. Play around with the curves to brighten up the image.
Output 189, Input 146
Output 105, Input 90

Step 2: Selective Color
Now we're going to achieve an interesting colouring. Selective Color is my favourite Photoshop feature to do that because it is very precise. Make a new Selective Color adjustment layer. We want to reinforce the greens so we will play around with Yellows, Greens and Cyans. Also with Blues and Whites to make the sky have a weird shade. Finally, with Neutrals and Blacks to tone up the whole image.
Yellows 49, -71, 5, 0
Greens 100, -100, 100, 100
Cyans -100, 100, 100, 85
Blues 91, 23, -3, 0
Whites -5, -2, 2, 0
Neutrals -23, -4, 11, 0
Blacks 0, 0, 0, 45

Step 3: Selective Color
This green looks kinda yellowish, right? A new Selective Color adjustment layer will fix that. Again, play with Yellows and Greens.
Yellows 100, -3, -6, 2
Greens 100, -20, -100, 100

Step 4: Hue/Saturation
The result we are trying to achieve is a little faded but not dull image. So, before making the image look faded we are going to make its colours more saturated. Make a new Hue/Saturation adjustment layer and play with the Master and Greens.
Master 0, 25, 0
Green 0, -13, 0

Step 5: Texture
Let's add some textures to make the icon more interesting. You can use a light texture with some blues and/or whites and some darker spots. I used this texture by
idiotxbeauty. Make a new layer with the texture and set the Blending Mode:
Soft Light, Opacity 64%

Step 6: Texture
Let's add one more texture. This time use a texture which is a gradient - from whites and blues to black. I used this texture by
candysky. Make a new layer with the texture and set the Blending Mode:
Soft Light, Opacity 100%

Step 7: Gradient
After you have achieved a nice looking image it's time to make it look faded. There are many ways to do that but in this tutorial I'm going to use Gradient Fill. The colours you are going to use depend on the your image. Make a new Gradient adjustment layer:
Gradient Type: Solid
Smoothness: 100%
566d7c, fddea2
Style: Linear
Angle: 58,24
Scale: 100%
Set the Blending Mode:
Lighten, Opacity 40%

(final result)
Notes:
You can use this tutorial for other types of images:
1. For images that don't have any greens or have many yellows - remove the Selective Color Layer in Step 2.
Example:
from this
to this
(with some sharpening)
2. Bright images that have lots of whites, neutrals and blacks - lower the Curves layer's opacity to about 50%.
Example:
from this
to this 
to this 
Difficulty: medium
Program: Photoshop CS5
This tutorial will show you how to brighten up a dull image and add some nice textures. Best results are achieved with images with greens like the example - mountain landscape. I am going to show you more results in the end of the tutorial.
Step 1: Curves
Curves are great to fix image's brightness, contrast and colours at the same time. Make a new Curves adjustment layer. Play around with the curves to brighten up the image.
Output 189, Input 146
Output 105, Input 90

Step 2: Selective Color
Now we're going to achieve an interesting colouring. Selective Color is my favourite Photoshop feature to do that because it is very precise. Make a new Selective Color adjustment layer. We want to reinforce the greens so we will play around with Yellows, Greens and Cyans. Also with Blues and Whites to make the sky have a weird shade. Finally, with Neutrals and Blacks to tone up the whole image.
Yellows 49, -71, 5, 0
Greens 100, -100, 100, 100
Cyans -100, 100, 100, 85
Blues 91, 23, -3, 0
Whites -5, -2, 2, 0
Neutrals -23, -4, 11, 0
Blacks 0, 0, 0, 45

Step 3: Selective Color
This green looks kinda yellowish, right? A new Selective Color adjustment layer will fix that. Again, play with Yellows and Greens.
Yellows 100, -3, -6, 2
Greens 100, -20, -100, 100

Step 4: Hue/Saturation
The result we are trying to achieve is a little faded but not dull image. So, before making the image look faded we are going to make its colours more saturated. Make a new Hue/Saturation adjustment layer and play with the Master and Greens.
Master 0, 25, 0
Green 0, -13, 0

Step 5: Texture
Let's add some textures to make the icon more interesting. You can use a light texture with some blues and/or whites and some darker spots. I used this texture by
idiotxbeauty. Make a new layer with the texture and set the Blending Mode:Soft Light, Opacity 64%

Step 6: Texture
Let's add one more texture. This time use a texture which is a gradient - from whites and blues to black. I used this texture by
candysky. Make a new layer with the texture and set the Blending Mode:Soft Light, Opacity 100%

Step 7: Gradient
After you have achieved a nice looking image it's time to make it look faded. There are many ways to do that but in this tutorial I'm going to use Gradient Fill. The colours you are going to use depend on the your image. Make a new Gradient adjustment layer:
Gradient Type: Solid
Smoothness: 100%
566d7c, fddea2
Style: Linear
Angle: 58,24
Scale: 100%
Set the Blending Mode:
Lighten, Opacity 40%

(final result)
Notes:
You can use this tutorial for other types of images:
1. For images that don't have any greens or have many yellows - remove the Selective Color Layer in Step 2.
Example:
from this
to this
(with some sharpening)2. Bright images that have lots of whites, neutrals and blacks - lower the Curves layer's opacity to about 50%.
Example:
from this
to this 