Same process as Paul mentioned, but I saw mine (wood) at an angle -- to the assumption that the wood wedged together can take up most of the twisting load on the ferrule.
You may also try to wrap carbon fiber around the loom to make your own ferrule. I have not try that myself yet, but it is a thought.
I make mine out of spruce -- it is strong to its weight. Redwood is lighter but brittle. Cedar? -- I heard that it is better , but I cannot find that in my area (may be I have look hard enough.)

: They are called ferrules, and, while the commercial ones are sleek, you can
: probably make one yourself from an 18 inch piece of aluminum tubing, or
: PVC pipe. Get the tube first and saw the paddle in half. Then whittle 9
: inches back from the cut ends of the paddle to fit snuggly inside the
: tube. Glue one half of the paddle to the ferrule, but let the other end be
: free to come out when you want to take apart the paddle. A hole drilled
: through the ferrule and the free end of the paddle can be used with a
: cotter pin or linchpin to lock that part of the paddle in place.

: A commercial source is: http://www.whitesquall.com/catalogue/parts.html

: Scan down their list and you'll find they have stainless steel, fiberglass,
: and aluminum ferrules.

: Searching www.Google.com for "kayak paddle ferrules" showed
: several links back to previous discussions on this bulletin board.

: Hope this helps.

: PGJ