[pixelherder]

For selective focus I find a far more realistic method than just using Guassian Blur (which is a blanket mixing of pixels), is to turn the quick mask on, gradient tool (black to white), click and drag to 'colour in' your areas of focus, then turn off the quick mask and go into Lens Blur.

Make sure you select an aperture shape similar to your camera iris and play with the levels. Because you are blurring into a gradient selection, rather than masking a gradient into a blur layer you tend to avoid the ghosting and soft focus effect of a vaseline-like filter. Much more realistic.

Add a touch of grain afterwards for a consistent level of quality and to tie everything together.