This is a great technique to jazz up Illustrator files quickly and easily.
This technique will work with just about any Illustrator image. The only thing to remember is that the final product's size parameters will be set by the final Photoshop image and not Illustrator.
The most important thing to do here is to make sure you make each element of your image a separate layer in Illustrator.
Once you have all of the elements on their own layer in Illustrator, select FILE>EXPORT and choose Photoshop (PSD) as the format. This will save out your file as a layered Photoshop file.
From this point you can add layer styles, additional layers, masks, drop shadows, bevels, gradients, etc...
Another great part about this technique is that if you created typography in Illustrator, the typography will be fully editable when exported to Photoshop!!
The final product I ended up with was this after adding the typography in Photoshop and adapting the file I started with in Illustrator to a book cover template.
Hope you enjoyed the tip!