I thought I'd play with an image today and try treating the same image a few different ways. The original is at the top.
In the second image I just applied a filter called Lacquer and played with combinations until it looked completely different.
The third, I made a second layer, cut out the flowers for the top, and made the base layer black and white.
The next one I applied a gaussian blur to the base layer. I overdid it on purpose for the example.
The final one took a bit more work, I've never tried it before and my old photoshop requires a bit more work. I created three layers, one for the white background, one for the picture background and one for the flowers. On the picture background, I painted a slight black line around the picture, then went to transform/perspective to skew the picture and shrink a little, then I applied a drop shadow to it. Top layer I cut out everything but the flowers and skewed them slightly bigger at the top. I painted in some edges on petals that were clipped until the looked more natural, then I cloned in some of the background on the second layer to remove any parts of the flowers poking through on that layer. Them I applied a larger softer dropshadow to the top layer to give it a little depth. Check everything, last bit of clean up for edges and then flatten.
Hope it gives you some ideas.