We'll drag the existing layer to the New button on the bottom of the layers panel to create a new copy.
Now we'll go to the Filter menu and choose Gausian Blur.
We'll change the blur amount just enough so we lose a little detail of the image.
Now we'll double-click on the layer to edit the layer.
And we'll change the blending mode to overlay. This allows the original layer underneath to show through.
We can then adjust the amount of the effect by changing the opacity.
And now we have a slightly enhanced image.