A couple things to remember when it comes to avoiding "lost" luggage (which really isn't in 99+% of cases - it's delayed)
Computerized luggage systems have eliminated almost all of the old "wrong airport" on the luggage tags, by tying the printing of the bag tags to the flight record. However, there is still a potential for error - if several people are getting bag tags out of a check-in printer, it is possible that they get switched in the hustle. So always check that the luggage tags on your bag have your name and itinerary. Before they go zipping down the conveyor belt.
The biggest source of delayed bags are short connections. Yes, I know folks don't like to sit around airports (though they will sit around on a cruise with no problem), but making sure you have a comfortable connection is, IMO, a plus all around. Neither you nor your bags will have to make mad dashes to the next flight.
The next biggest issue is close check-in for the bags. Even though you may have met the airline's deadline, you might encounter a TSA screening backup, down in the bowels of the airport. Remember, it's a government process, so they pretty much answer to no one when it comes to their throughput. And if the bag doesn't get through screening, it won't get on your originating flight.
Another issue is if you have a regional jet on any of your segments. These aircraft are the most likely to have load issues with baggage, or with large size bags. Sometimes, there is too much weight to fly, and airlines will bump the luggage. Or bags that are very large may get bumped in place of smaller, easier-to-fit bags. If small jets are the only option out of your airport, you may not have much control over this, other than booking longer connects.
Finally, the number of "mishandled" bags for US carriers in the most recent reporting month is 0.48 per hundred bags checked. This category covers lost, delayed, damaged or pilfered bags.