If you get bit, you need to get treatment ASAP. That IS the bottom line. The bit might have been dry, but you can't assume that. Unless you are not far in and can hike out, this is where the SPOT or PLB comes in to play: you get bit; you hit that button and get the signal out.

Better to avoid the situations that lead to getting bit. Generally, rattlesnakes like to hang out under bushes and at the base of rocks. They like places where they can stay hidden and still see things go by. Think "can I see the area around where I am placing my hands and feet" before sticking them in those spots. That is one of the beauties of staying on a well used trail, you can generally see what is around you.

The seasons are important too. When mapping in the Big Maria Mountains in Jan and Feb, we rarely saw a snake. But in March, they were all over the place. We were seeing 15 rattlesnakes a day and most of them large and fat. I never would have guessed there was that much to eat out there. Even with a group, someone needs to know what to do and it is important for everyone to know how to navigate and get out ASAP if necessary. The week after the 1st time I went to San Pedro Martir for reconnaissance, a group of 4 or 5 went to the same area we went in to. One of the party was bit by a rattler in the thigh stomping though manzanita. They did not know what to do and the guy died on the 3rd day of them trying to get him out. This was well documented and was a comedy of errors unfortunately, probably the worst of which was the lack of navigation skills in such a remote area. You can get out of this area in 1 long day with 65 lb packs under normal conditions.