step 1 of 8
First, I cropped the finger to just below the first knuckle.
step 2 of 8
Then I found this image of a bowling pin. Here's the link:
http://www.donerite.com/global_images/amf_used_notcoated640.jpg
step 3 of 8
Then, using liquefy and the pin pic to match the shape, I created the finger pin. I used the magic eraser tool to remove parts of the pin photo to easily get a mask for the stripes and AMF logo on the pin then dragged the mask to match the finger pin. Then using contrast, I changed the shade on the finger pin.
step 4 of 8
For the next step, I found this image for the background. Here is where I found it:
http://visualparadox.com/images/no-linking-allowed-main/bowling.jpg
step 5 of 8
Using the created finger pin, I dragged it over to the background image, resizing it to fit each pin, one layer for each pin. This shows only two layers but you get the idea.
step 6 of 8
After adding all the pins, I adjusted each with brightness/contrast to match the lighting effect to give it more realism. I also burned each just a bit to give it more dimension, as well as blurring edges to smooth out some of the rough edges.
step 7 of 8
To make the bowling ball with a finger groove look, I used the same process with liquefy that I used with the pin. I found a cartoon bowling ball to use as a pattern for the mask.

sources used for this step:
step 8 of 8
After using liquefy, I matched the shape of the finger with the shape of the ball. This is also another layer. I then matched the shadows and holes of the cartoon bowling ball and used the mask to adjust the shadows and make holes on the finger ball. This also includes a motion blur to give the ball motion, but I had to cut back, only because I didn't want to loose detail of the ridges in the finger, so I had to use my best judgment as far as how much motion to include. Then some final touch-ups on the pins with burn, blur and brightness/contrast.