Shadow Help

[Joezilla]

I found a quick down and dirty tutorial at the Wacom website ( http://www.wacom.com/tips/tip.cfm?ID=51&STEP=1&category=Photoshop )
and it looked fun, but I have a question. Take a look at the end result and see if you can spot my issue:

See the shadow of the fish in the background? What is the best way to correct the error?

[MarcelSpijker]

What i would do is make a selection of the fish.

On a new layer fill the selection with black.

Transform it so it looks laying on the ground and then play with opacity.

Here a quick and dirty atempt.

[123456789]

Don't forget to also use 'Gaussian Blur' on the shadow layer, and remember that a shadow gets more opaque the closer it is to the subject.