For any damage that's not bad enough to toss the tire, but bad enough to desire a bit of reinforcement....

I'll do a full glue repair on the inside of the tire with "Velox" rim tape, complete with light scuffing (very light sanding here to avoid damage to the cloth that's right under the rubber), vulcanizing fluid, and careful application of the tape. The tape is designed for keeping a tube from escaping through small holes, so it seems a fitting use for it as a tire boot. Just be realistic about the damage. Don't expect a compromised tire to be boot-able no matter how careful you are. Also, be sure and use a long section of tape to cover far more than just the hole. I usually use 3 inches or so. Good luck, and I DO NOT guarantee the results of following my advice.

-Jeremy