I find that the simple blur tool works very well for smoothing out pores. For pimples, I recommend the healing brush tool. Do mask off the area if what you're working on is close to an edge boundary as the healing brush sometimes makes the colours bleed.
1. Select face region from bgd layer as duplicate A
2. gaussian blur 5 - 8 pixels on duplicate A
3. duplicate result of step 2 (duplicate A) as duplicate B
4. gaussian blur 5 - 8 pixels on duplicate B (optional step for more dramatic effect)
5. set duplicate A to 50% opacity and blending mode to darken
6. set duplicate B to 50% opacity and blending mode to lighten
7. using history brush and the original snapshot as history source, paint back the sharp edges (eyes, lips, teeth, etc) with maybe 50% opacity.