The shield - mounting the stacky headers:

display panel
(click for a larger view)

Overall, this is a simple project. You don't have to worry about getting the right value component in the right place, burning semiconductors with the soldering iron, or blowing MOS components with static electricity. You can probably start soldering with nothing more than a quick look at a picture of the finished product.

There are some tricks though.

It's easy to make a shield that looks ugly and takes two minutes of fiddling every time you try and plug it into the Arduino. It's only slightly harder to make one that looks good and seats easily.

The first trick is to use the Arduino itself as an alignment jig.

Set the shield on the Arduino and press the stacky headers through the holes. This puts them exactly where they need to be for future use.

Flip the assembly over and press the board down so it rests on the stacky headers.

Now you want to tack the first and last pins of each header in place.

The solder joints don't need to be great. They just have to hold the header in place long enough for you to solder the rest of the pins.

Pull the shield off the Arduino and get ready to solder the rest of the pins.

You can see the tack joints better by clicking on the image and seeing it full size. They aren't fantastic connections, but they're good enough for the next five minutes.

With the tack joints holding the headers in place, work your way down the row soldering all the inner pins.

Don't touch the tack joints on the end pins. We'll get them on the next pass.

Once all the inner pins have been soldered, go back and make good connections on the ends.

Check the alignment by seating the shield back in the Arduino. It should fit smoothly and without fuss.