I supposed you're a "medium user" of Photoshop. I'm not really interrested in the leaves here, so just draw them using this example.

RATHER REALISTIC LOOKING STRAWBERRY UNDER PHOTOSHOP

 

1. Draw the shape of a strawberry. Let say something like this.

 
2. Chose a palett of 6 red's tone. (You will need more or less colors according to the size of your strawberry. Just remember that the bigger it is, the more different colors you will need.). Note that the last color is really lighter than the previous one.
 
3. Choose one of the medium color and fill in the shape.
 

4. Add lights and shadows using the color of your palett. I can't tell how to draw it exactly, it all depends on your strawberry's shape. The darker colors are usually "under" the objetc, and the lighter colors on the "top" of it.

 

5. Now you will have to randomly put dots on the border of each colors. Put dots of the lighter color into the darker one. And put dots of the darker color into the lighter one. You should obtain something like this.

   
6. Repeat the operation for every color and every border. This should looks like this.
 
7. Now add a few spots of the lighter color of your palett into the lights on your strawberry. And your done!
 

Result