wrote in message
Any tips? Should I be using a saw guide of some kind? I have a feeling
I will get better results just cutting one piece of wood at a time,
instead of trying the two clamped together trick.

A saw guide would make it quite a bit easier. Here's a few workable but
cheaper ones. The price goes up from there.
http://www.leevalley.com/wood/page.a...21&cat=1,42884
http://www.leevalley.com/wood/page.a...55&cat=1,42884
http://www.leevalley.com/wood/page.a...66&cat=1,42884
http://www.leevalley.com/wood/page.a...69&cat=1,42884