Super fast summary:-
Wet areas or ones with a lot of exposed metal pose the highest shock risk.
Confined areas or reaching into equipment pose a higher risk of fatality by trapping you during an electrical contact.
Treat everything as live even when seemingly isolated/disconnected due to the risk of backfeeds from other circuits.
Ordinary work gloves can reduce the risk of a serious shock greatly.

Safe electrical training can not be replaced with 1-5 day slideshow classes.

One thing I didn't mention in the video is the horrific way most fatal shocks occur. Workers making contact with live connections while in confined spaces or getting trapped reaching into equipment often die of oxygen starvation, as their ability to breathe and the heart's ability to pump blood is prevented by the flow of current through their body. Even when they black out they are often still passing current, and if not discovered quickly will not survive.

Gloves. If you touch an electrical connection with your bare hands, the only insulation between them and a VERY conductive interior is a layer of dead skin cells on the surface. They do not have a voltage rating and in the event of contact the skin's resistance rapidly breaks down. In the event of muscle contraction a larger area of skin makes contact and high current will flow.
While there are specifically rated live-work gloves, for less critical scenarios where you are not deliberately going to be handling live metal, a set of common work gloves adds a valuable extra layer of insulation to your hands. At the very least they can reduce the shock current of an accidental contact. The insulation of gloves is greatly reduced if they are wet.

CPR (Cardiopulmonary Resuscitation). This is a very volatile area, since every country has its own standards and there is a lot of folklore from the past.
The primary purpose of CPR (chest compressions) is to keep blood flowing around the body to prevent brain death. The theory that providing CPR to someone with a beating heart is dangerous has been disproven. Instead of wasting time trying to find a pulse, it is now considered a good option to immediately start chest compressions on an unconscious shock victim to get the existing oxygenated blood flowing to the brain. The act of compressing the chest can also cause airflow in the lungs, although the "breath of life" (mouth to mouth resuscitation) is useful if there is more than one person present.
In the event of the heart being in a state of fibrillation it is essential that it is resynced by an external defibrillator. Every second counts, as the chance of heart resync drops rapidly with time. Even when the paramedics arrive, continue doing chest compressions until told to stop.

Here's real video footage of CPR and a defibrillator being used on the victim of a pool electrocution. The fact the unit delivered a shock pulse indicates that it detected the heart was in a state of fibrillation, but still recoverable. The shock did resynchronise his heart.
NEVER work on anything electrical while standing in water, as a shock will involve massive current.
   • Cops Use CPR To Save Man Electrocuted...  

Here are some video examples of shocks, noting that I will NOT be posting excessively graphic ones, and definitely not overhead line contacts.

Worker at top left corner makes contact with conductors of a live cable he is holding. Because the current is hand to hand, he manages to drop and gets lucky when the cable follows him down, but seems to short out as he hits the floor. Note how his arms have gone up to his chest and are so rigid that his left arm barely moves when it lands on the desk.
   • ✔ DON'T PLAY WITH ELECTRICITY (Shocki...  

Example of contact with grounded metalwork while working on live circuitry. Legs in contact with bare metal, gripping on with one hand and coming into contact with an electrical connection with the other, made worse by his head contacting the metal ductwork too. I don't know what the outcome of this was. The fact he fell clear increases the chance of survival. This is a grim video.
   • Repairman electrocuted "WEIRD"!  

Expect the unexpected. Guy being shocked by roller shutter that becomes live is pulled clear with a scarf.
   • Quick thinking | Man saves his pal fr...  

This video shows a guy getting a shock from the electrical trigger on a pressure washer (!!!).
It shows how a shock can affect part of your body, but still leave you able to do something about it. He survived.
   • Lucky 'Stiff' Saves Himself From Elec...  

This shows a horribly common shock scenario in the entertainment industry, sometimes caused by old or faulty tube/valve amplifiers. It results in a voltage difference between the strings of a guitar and a microphone. Note the loud squealing feedback noise when the guitar player on the left of the stage reaches up and grabs the microphone before collapsing.
   • Member of Hot Hot Heat electrocuted!