Step 1
For my tutorial, I'll use a picture of my favorite player, Yao Ming.

The size of the image is 115x175. Now, in Photoshop, go to Image>Image Size. Make sure "Constrain Proporations" is on. In width, type in, let's say, 300. The picture would be pretty pixellated huh? Don't worry, we'll fix that soon.
Step 2
Duplicate a layer of the pic. Go to Filter>Gaussian Blur. With a 2.0 setting. Now on the layers palette, choose the Soft Light blend mode. Merge Down the layers. The picture should now look like this.

Step 3
The picture is still a bit pixellated. So we'll duplicate step 2 again, except that this time, the Gaussian Blur will have a setting of 1.0, and set the blending mode to "Screen".

Step 4
Now, go to Image>Adjustments>Brightness/Contrast. With a setting of: Brightness: -25 Contrast:+10. Then go to Filter>Sharpen>Unsharp Mask and apply it with settings of 50/1.5/10. The final picture should look like this:

Step 5
Final Step. Try this out and start patching! Hope this tutorial helped some aspiring patchers out there.