All horses should be approached the same, with caution and care, never take anything for granted with horses and expect anything to happen.
Starting with young/nervous horses. Treat them as if they have never been shod before. keep the environment free from anything, no objects should be near not even your tool box, just take a tool at a time avoiding cluttering your work space. Use a handler if you can, maybe a food distraction as well if the horse is becoming agitated. Slow and steady needs to be applied to the situation, always communicate with the horse, give it a few strokes and pats to comfort it. Do not snatch at the legs, ask for them and be patient, don’t rush the horse as this will only worry it. The back and forth nature of leaving your toolbox out the way will mean the horse has to drop and pick up its foot lots of times which is good practice. Maybe for certain horses cold shoe it or very very lightly burn it on so it gets used to smoke at a steady pace. Shoeing another horse that is very well behaved whilst tying or holding the nervous horse next to it is a good way to get it used to the sounds, sights and smells of the farrier. Hopefully by the horse not reacting to smoke or nailing or picking up legs the horse will come around and calm itself down. Continue with the task and give the horse time until you complete the job. Try to avoid letting the horse win though, this can lead to other behavioural traits that will worsen with time. Unfortunately this is a fine line between being caring and patient with the horse and the horse then playing up on it. Letting a horse get away with bad habits like kicking, rearing, biting and collapsing will lead to it thinking that these habits are acceptable. Instead making an environment where these things won’t be achieved is essential.
For naughty and misbehaving horses the same things should all be applied but with a firmer hand. Horses that think they can now get away with kicking need to be dealt with swiftly and firmly. Chifneys, twitches, bridles, holders, food and other company should all be tried if the problem is too bad to handle without and even if that fails ask a vet for an injection to sedate the horse. Sedating is expensive though and something that the owner will want to avoid. Instead try the other methods of restraints and distractions I said earlier and try and shoe the horse that way. With a competent holder the horse should stay relatively still, ask for each leg as you usually would but be making sure you are fully aware of exit points and that the horse may strike out. Usually these horses are time bombs and will get bored so try to have everything ready with a set plan, no time wasting wants to be done when you are under a badly behaved horse.