Do the twist, uploaded to Flickr by James Snape.
Canon 400D, Tamron AF 55-200mm f/4-5.6 Macro lens - 1/40 sec, f/8, ISO 100
Since I can't afford nor make enough use of a dedicated tilt-shift lens I have to fake it but one of the main benefits is you get images that look like miniature models. This is my method...
First you need to start with an image that will end up looking realistic. It needs to be taken from quite a distance and with a long lens to compress perspective. You also need to be above the subject just as if you would be when taking a photo of a model.
Next take the image into Photoshop and duplicate the background layer (I always work non-destructively).
We are going to use the lens blur filter with a depth map to indicate where the blur should be so add a layer mask to the duplicated layer.
Select the gradient tool and select the black to white gradient, reflected (4th icon from the left) and reverse options as shown below.
Then draw your gradient onto the layer mask. As we have the reverse option ticked you start at the point where you want the focus to be and move to the top or bottom of the screen. In this sample I put a slight slant in to ensure the focus hits both the people and the hut.
If you Alt-Click and then Ctrl-Click on the layer mask you should see something that shows a narrow band of white with a slow fade to black at the top and bottom of the image. Note that for the best effect you should have a long smooth gradient and not a short transition to black.
Hit Ctrl-D and then Alt-Click on the layer mask to switch back to the source image. Then make sure you click on the image icon to the left of the layer mask before invoking the lens blur filter (Menu > Filter > Blue > Lens Blur...). You need to select "Layer Mask" for the source and, since we have a white to black gradient, ensure that Invert is checked. The rest of the options just control what kind of bokeh you are after. When you are happy click OK and wait, possibly for a long time as the filter is quite expensive to run.
When the filter completes, just delete the layer mask to reveal the miniaturised image.
To make the result even more believable you can try and emulate the kind of lighting used when photographing miniatures. Boost the saturation and contrast with curves and you will have the final result at the top.