Another fun thing to do is to make a color photo into black and white and retain color.
I made a copy of the original layer and then set the layer to not show. I ran the black and white photo filter on the copy. After making adjustments to the settings I applied the filter. I then determined what parts of the color photo I wanted to keep and erased the others letting the color layer show through. I ran the darken and lighten filter to deepn the edges. The last effect I applied was a touch of glamour glow to highten her skin color.