I use a magic wane set to a number to what the object hue is[like set on 30 and use + to touch the objuct . If to high then set it to 20] and cope and paste it so it be a new layer. or use a line drawing to draw what I wish then cope and paste it so it be a new layer and If I overdraw I can use a transparant brust to fade or erase what I do not need. and do not worry about mess ups there a undo or back arrow to get back to where you was Or i use a edge finder to trace what I wish and cope and paste it down. for when I paste it it makes a new layer. Just play around with the program you have there many ways to do the same thing.

what you see is not what you know; it in your face