Peter Bargh is founder of ePHOTOzine. He 's worked on leading photography magazines and launched the UK's very first consumer digital imaging magazine back in 1997. Peter also has a number of books and videos published on digital imaging and Photoshop.
Here's his tip:
"Cutting out some subjects from their backgrounds can be really tricky, especially fine detail, such as hair, or subjects with shadow areas where it's difficult to see the outline in the shadow, like this example of a sports car.
"The tyre blends into the shadow under the body so it's impossible to see an edge to make a good selection.
"There's an easy fix - work from a lighter version. If you are using Photoshop, this can be done quickly by making a curves adjustment layer.
"Go to Layer > New Adjustment Layer > Curves. This creates a new layer above the original. In Photoshop CS4 the unadjusted curve appears in the palettes on the right. In earlier versions you make the adjustment as soon as you create the layer.
"Pull the centre of the curve to the top left and the whole image will look totally over exposed, but, in this case, look how you can now see the tyre's edge.
"This adjustment has not affected the original image and if you delete the layer it will be back to how it was. But it now lets us work on the original as if it was the adjusted layer.
"Make the original layer active by clicking on it, and make your selection using the Pen tool, lasso, masks or other favoured method. When you're happy delete the adjustment layer and save the selection."