If you’re using an earlier version of Photoshop CS6, then you won’t have the Tilt-Shift filter at hand… here’s a tutorial on how to apply a miniature effect
Inside the Blur filter, set the Radius to 10px. Use the preview window to see just how the blurring has affected your image and boost the Radius slider for a heavier blur if needed. Hit OK and notice how the filter has attached itself to the layer. Double-click on the filter’s name to re-edit at any time.
Press G for the Gradient tool and then set your Foreground and Background colours to black and white (D). At the top of Photoshop, choose the Foreground to Transparent gradient type, select the Reflected Gradient option and untick Reverse, but tick Transparency.
Click on the white mask of the filter in the Layers palette. Click and drag the Gradient tool from the centre of your image outwards. This will reveal the clear image underneath. The longer the lines are that you make, the larger the corridor of focus will be.