Indeed, the correct recovery technique is all important; equally important is an understanding of what's going-on during the final approach phase.
In large multi-engined aircraft i.e. B747 or similar (with 2 engines out), there comes a time when you must reduce your speed below Vmca(2) towards Vref. Should it then (subsequently) become neccessary to carry out a Go-Around you cannot simply apply max thrust and point the aeroplane away from the ground. Your speed will be below Vmca(2) and you will lose control of the aeroplane. Therefore, you must continue descending whilst "cleaning-up" and accellerating (increasing thrust commensurate with maintaining control of the aeroplane). When Vmaca(2) is achieved it's only then that you can apply max thrust and start to climb away from the ground with a slight bank towards the live engines (the exact bank angle is published within the Flight Manual and it will be of the order of 3 to 5 degrees).
It's therefore vitally important that you're "aware" of what that particular speed actually is and that you keep it somewhere in the back of your mind for the Go-Around case. Carrying out a double assymetric Go-Around certainly concentrates the mind and that it will demand "precise" handling of the aeroplane. To alleviate the Go-Around case you should considder (in advance) asking ATC for a sterile runway; particularly when you're committed to land i.e. when you've reduced your IAS below Vmca at, say, 1500 feet.
A Go-Around is usually neccessary due to another aircraft being on the runway; thus preventing you from landing. Many times that I've been in the simulator (and carrying out such procedures) it's usually the case that the instructor will induce the double assymmetric Go-Around... it's part of your licence requirement. However, in the real world, if you're making your final approach (committed to land) and the controller says "Expect late landing clearance due departing traffic"... considder this... if you can see that the depature traffic is well on the way to getting airborne; go ahead and land! Why? A Go-Around from three or four hundred feet will result in disaster. It's better that you're on the ground and taking to the grass than trying to fly an impossible procedure that will only result in a pile of mangled aluminium somewhere outside of the airfield perimeter.
Take care y'all
TCF
Be aware that on a Turbo-Charged engine, Vmca will slightly increase as you climb. This is due to the fact that the turbo controller is sensing temperature and pressure (density) and will apply "boost" in order to maintain power with altitude gain.