<p>When adding new properties to classes, I find myself typing the same things over and over in xcode:</p>

<ol>
<li><code>add TYPE *NAME;</code> (in .h interface)</li>
<li><code>add @property (nonatomic, retain) TYPE *NAME;</code> (in .h)</li>
<li><code>add @synthesize NAME;</code> (in .m)</li>
<li><code>add [NAME release];</code> (in .m dealloc)</li>
</ol>

<p>(I'm in a non-garbage collected environment.)</p>

<p>How can I do this automatically?</p>

That sounds about right.  IIRC, the Objective-C 2.0 doc says you might be able to leave out step #1, but otherwise I don't know of any shortcuts.
You could probably write a user script to do so within Xcode.  See
http://www.mactech.com/articles/mactech/Vol.23/23.01/2301XCode/index.html
.