DIY Cat Trees and Scratching Posts
Horizontal Scratching Pad
My own instructions for building an inclined scratching pad (similar to the Alpine Scratcher, only made of wood and sisal instead of cardboard).
Build a Scratching Post
Basic instructions and material list for a two-level scratching post. Unfortunately, the photos were broken when I visited, but there is a good graphic illustration for a visual clue of the finished product.
Do-It-Yourself Cat Tree
The venerable Amby offers another take on the PEta instructions for a 3-tiered cat tree, offering suggestions for modifications and improvements.
How to Build a Scratching Post
Clear instructions from Cats International for building a simple scratching post wrapped with sisal (a scratching material favored by many cats).