Get a crane riggers ticket to satisfy H&S, and then forget 90% of what they tell you about actually rigging loads....
And never let a "crane rigger" strop up your load, as there is a really good chance it will come off / fly apart / etc while you are flying.
If they insist just ask them how often they are working in 100 km/hr winds? Not many crane operators are happy to b working in wind, but that is where our load lives!!
Also be careful with what rigging you by. Barry I think, have put an age on their ropes, from date of manufacture! So you buy a couple of brand new longlines, one goes in the cupboard, the other one gets used once a month and is looked after really well, but after a couple of years you have to throw them both out!!
Another guy buys one and uses it everyday in the dust and grime and can use it the same length of time if it passes "visual inspection"...