You're not going to grab the slide and stop it from recoiling, your not going to count the shots or be able to discern the best course of action from whether or not their finger is on the trigger or pointed forward.
Trying to block the hammer with the web of your hand--dont be stupid. You'll get killed thinking that this is legitimate strategy.

Handguns are not at all innacurate. And they are plenty lethal. Anyone who says otherwise proves that they know nothing about handguns.
Even if they were lacking in accuracy, the distance that we are speaking of renders that inacuracy moot. While a shot from some pistols will likely not kill you instantly ---depending on where the bullet hits--- the heavier calibers will knock the hell out of you, possibly even spin you around. Which pretty much ensures a second shot, which will have the same result, thus ensuring a third shot, so on and so forth, until you're dead. Even where this is not the case, the body goes into shock fairly quickly. If you get shot, you WILL go into shock, very soon, once that happens you can forget about being an effective fighter.

If someone wants to kill you they wont give you a cigarette before hand. Would you?
If you were going to kill someone would you really give two horse's sh++s about their "last request"? No.
Thats hollywood.
Killing does not care. Killing has no room for such trivialities.

Just because someone is robbing you does not at all mean that they are morons. Nor should it be taken as proof that they are "untrained" in the use of firearms.
Training after all can be simple experience.

A lot of toy stores still carry those little plastic guns which shoot tiny pellets or disks. Get one. Hell get a squirt gun. Point it at your training partner. Do this in such a way as to simulate whatever scenario you want to train for. If its a robbery, then just ROB your friend. Rob his ass. If he gives you a hard time, shoot him. Shoot him and keep shooting him.
Once you put yourself in the shooter's perspective, youre going to see just how full of **** people are when they talk about their super ninja tactics for taking guns away from people ready to shoot. Once someone gets a bead on you, if they really know what theyre doing, thats it. There is virtually nothing that you can do (other than comply) that will not get you shot. The only chance that you have is that they make some kind of tactical mistake, which as i implied a moment ago, they will not do if they know what they are doing.

About someone who's serious about killing you--if theyre smart then theyll kill you before you have anything to say. If they are not so smart then they may want to gloat or laugh for a minute...put you at their mercy and ridcule you while you're there--but mostly thats TV. If they want to kill you because theyre in a rage they sure as he11 arent going to waste time laughing, and if they come at you in a premeditated or proffesional manner, again they are not likely to waste time laughing, theyre just going to kill you.

About someone that simply wants to rob you, well again i would say that its entirely situational. ASSUMING that it is just one person--ASSUMING that they are using a handgun, (not in comparison, a mac 10 or sawed off shotgun) and ASSUMING that they are not too smart about it, what I would emphasize is that IF you get a chance, thats all you will get, A chance. One chance. Thats it. Whatever you're going to do, it better work, and it better work the first time, and damn quick to boot, because if it doesnt you WILL get shot.

Its a lot easier to shoot someone thats trying to take a gun away from you than it is to take a gun away from someone that is trying to shoot you. All you have to do to confirm this is get a "gun" and a training partner. Test it out for yourself, from the shooter's perspective.
If i offer anything in the way of tactics, it would be to control the muzzle until the shooter is no longer able to pull the trigger. (Pretty vauge isnt it?) Whether you knock him out or outright kill him, whether you take the gun from his hand or overpower him into submission, whatever, you cannot allow the weapon to remain fixed on you. Thats pretty much all that i can say. Your strategy would be more realistic if it incorporates the likelyhood that the gun WILL go off during the struggle for control. Guns being what they are, when they discharge they tend to do a lot of damage to whatever is in front of them, so make sure that YOU are not among the list of things in front of the weapon when it fires.
Thats it. Sorry for the long post.