I try to guard against the most likely bad occurrence. At an airport or prepared heliport, where I'm sure there are no wires, I do a faster approach, but to an unprepared scene, where the likelihood of unseen wires is greater than the likelihood of an engine failure, I make a very slow approach, at least for the final couple of hundred feet. There are wires everywhere, and they can be almost impossible to see until you're within a few feet of them. Making the approach slow enough to allow stopping to a hover, and then climbing back out, gives me the best chance to avoid wires. I don't like vertical takeoffs, but doing one from a scene is safer, IMO, than trolling for wires on a normal takeoff. Playing the odds gives me the best chance of surviving and making another flight, and the odds favor slow, steep approaches and vertical takeoffs from unprepared scenes. From a runway, obviously a normal takeoff staying outside the avoid area of the h/v diagram is safer, and that's what I use when I can. It all depends on the situation.