I'll tell you what I do, and also what suggestions I have heard that sound good. I use a heavy duty tripod case that I bought at B&H some years ago. I carry the tripod and sometimes a light stand, if I expect to need one. Then I pack my underwear, a sweater, and/or other clothing in the case for padding. I've never had any damage yet, but you never know. The case has a clear plastic-covered slot for a business card, and I insert mine there, as it has my address, phone #, cell, etc. I lock the zippers closed with plastic electrical wire ties to prevent accidental unzipping. TSA folks will cut them on occasion, but not always.
Good ideas that I have heard:
1) Buy a pvc pipe large enough in diameter to accomodate your tripod. Glue a cap to one end and a threaded adapter to the other, and a threaded plug to fit in the adapter. Lock the threaded plug with duct tape. Indestructible.
2) If you have a lot of gear to ship, buy a Golf Guard:
http://www.golfguard.net/golfguarddeluxe.html
They are quite reasonably priced and designed to protect golf clubs from baggage handlers.