To enchance a selection choose from the following actions:
Selection tools options
Select any selection tool
and use the tool's options as follows:
Add To - add to existing selection border.
Subtract From - substract from existing selection border.
Move selection border
To
move a selection border choose use any one of these selection tools
and select in Tool's Options palette mode to
New.
Refine selection
Option ⌥ + Command ⌘ + R
- Use the smooth slider to create a smoother outline.
- Use the feather slider to soften the edges of a selection.
- Use the size slider to shrink or enlarge your selection edges.
Click

to reset values.