How to get speckled shading in Photoshop?

I am trying to achieve, for lack of a better term, a speckled shading in Photoshop. I'm not getting the right effect using noise (even with a gaussian blur) or setting the layer to dissolve.

Here are a couple of good examples of what I'm referring to (they are not exactly the same, but they seem to employ a similar style):

(less so the top edge, more so everything else)

I'd appreciate any help (and, if I'm referring to this technique incorrectly, please let me know)!

Answer

Here's how I do it (steps correspond to pictures).

1. Starting shape to shade.


2. Create copy of shape with color of the shade (or highlight) you want to "speckle" and make sure the layer is above the original shape


3. Create a mask on this layer (3rd button from the left in layers palette)


4. Ensure that the mask is still selected and fill this mask with 50% gray


5. With mask still selected, go to filter > noise > add noise


6. Use the eraser tool with lowest hardness and the appropriate size on the mask where it is needed (in this case, the whole upper left part of the orange so that only the shadow remains).