Step one, choose the pen tool
Step two, make a path
Step three, right click and press on make selection
Step four, choose the brush and change the hardness to 0
Step five, change the settings of the brush to: Soft Light
Opacity: 20
Step six, color.
I hope it makes it easier, it'll take you some time to make the path but it makes your life a lot more easier, well for me it does...