First time using Channels

For this image I first sketched picture from a sports magazine calander (SI)
I then scanned the image into photoshop and started to work in Channels.
After laying the Flat colors through the Channels option I then copied the work layer and stated to use Dodge and Burn. The lips and and eye lashes done were last.
Any comments, good or bad . . . and why, are very much appreciated. Thanks