Does anyone else just selectively filter noise or does everyone else just filter the whole darn photo?

Skies: EASY peasy.
1) dupilcate layer
2) magic wand select them at a low tolerance (10-20). To do this I simply keep on adding (alt+click) to the selection until my entire sky is selected
3) inverse and delete the rest of the image from that layer
4) inverse again and do gaussian blur
5) flatten layers

Alternatively you can skip step 3) and instead in step 4) use despeckle, dust/scratches or blur but NEVER gaussian blur because this will create a sharp, fake looking edge when you flatten layers