Just thought I'd show a few pictures for new-to-TTM folks out there. I feel like there have been a few questions about how to do this, and I certainly didn't really know what to do when i started, so I hope this helps a few people.
This is for TTM ROMLB, but something similar (without the bubble mailers) could be done.
Necessary Parts:
Bundling it up
Good luck!
A few links that I've found helpful:
http://autographsupplies.com/
Cheapest place for ROMLBs that I've found
http://www.sportscardforum.com/forum.php
Good database of player's TTM addresses, % success tracker and a nice tool to track your own TTMs.