A wise person knows that listening is at least 2 -3 times as important as talking. Once you key down you are letting the world know where you are. DF equipment has you dead to rights. If you transmit on a ham frequency and fail to identify yourself by your call sign, any ham would know you are not licensed.

Listening is license free and anonymous. One can learn a lot by listening.

In a SHTF scenario, few (including) the FAA would be far too busy to care about it anyway, but still one would want to transmit with both care and quickness, and then only if you know who you are calling.

Most any old stretched out piece of wire which is 20 to 50 feet long and 10-20 feet off the ground will do for a makeshift receive antenna. Not optimum, but probably good enough to cover many frequencies. That same random length wire could possibly damage or even murder your transmitter, though. An antenna necessary for a transmitter must be tuned for each frequency to maximize range and keep your transmitter happy and healthy. Not so for receiving.

I have been a licensed ham for many years (extra class) but still, if I set up at say a bugout location, I sure would not want to transmit unless completely necessary, and I would have pre arranged a time window and some sort of identity that the person I'm calling would know.

I would suggest as f4t has alluded to, have the equipment, practice listening all the time to know how to tune and use it.

Listen often and record the call signs you hear. You can easily look up the call signs you hear on http://www.arrl.org/home (at the top right is a search box where you can enter the call sign and find the name, city and state.) Thus you can get some idea of the distance the transmitter is from you.

go ahead and figure out a transmit antenna that would work when the time comes --- and until then keep your mouth shut.