Despite the bad spelling! .. this is a good technique for changing the colour of hair using layer masks.

This tutorial shows how to create a vintage photo effect by adding a layer of texture accross the whole photograph.

A really useful video which shows you how to add texture to your digital paintings by adding abstract imagery. The imagery that you add, does not need to be an actual real life image of the effect you are trying to create. This example shows how an image of flooring can be used to create an uneven rough effect on clothing. Using layer masks to create this effect means that this is a non-destructive process, allowing you to go back and edit the image at any time.

Use layer masks to whiten or lighten teeth.

By using layer masks and different settings on the brush tools you can create this shattered glass effect on top of any picture.

Learn how to create non-destructive gradients on text layers. This tutorial shows you how to create a reflection with text layers without rasterizing the type. The use of layer masks leaves the text layer editable for future use.

Excellent & easy to follow tutorial of how to mask parts of a photo and add or change the colour. Try adding subtle colour to the eyes and lips of a black and white portrait to create a striking effect.