Selective Blur in Ps (beginner’s instructions):
* Open the photo

* Make sure the layers palette is visible (“Windows” menu or hit F7)

* Right click on “Background”, select “Duplicate layer” and hit “OK”; a new layer “Background copy” appears and is in selected state.

* Select “Filter > Blur > Gaussian blur” from the menu… hold ALT and click on “Reset” that appears, click OK. Your image turned all blurred.

* Hold ALT and then click on the rectangle with a lighter ring in it, in the lower part of layers palette. A black box appears next to the layer contents thumbnail, at the same time the blur disappears.

* To make sure the black box is selected, click once on it (a frame should be visible). Click on another box to see the difference, but go back and click on the black one last.

* Press “b” or SHIFT B until you see a plain brush (nothing else!) selected in the toolbox and also justbelow the menu-bar (assuimng standard setup, workspace)

* Click on the little black-on-white square in the toolbox (select black+white foreground and background colors)

* Press “x” once, the foreground and background colors swaps places.

Now, you have a layer mask for a copy of the photo. The copy currently is all transparent – due to the black color in the mask.
By painting with white color in the mask – by strokes over corresponding parts of the image – you will get back the blur. Swap to painting with black and the blur will vanish again.

Set BRUSH “Opacity” and “Flow” to somewhere near 30% to have things happen slowly and try it out.
Clicking on the eye to the left of the layer will make it go on or off, so that you can check the difference.

Save the image as PSD or PSB to allow yourself to continue working.

As you believe you’re done, select “Layer > Flatten image” from the menu. Then “Image > Mode > RGB” and “8 bit…” to be able to save as JPG.