Using Quick mask.

The quick mask tool is good for when your editing your photos because it gives you better control over the areas you have selected.
To make a selection using the quick mask, press the Q key or select the quick mask icon on to tool bar.
You can preview and edit a selection in quick mask, the selection is a transparent pink colour. This helps you to see what parts you have selected and what you still need to select or even unselect.
The area which has been selected will not be effected as it has been marked, but you can edit this area by inverting your selection, this will mask off everything outside the orginal selection.