NH is a way of working and teaching horses and having fun with them with litle tools as possible. You try to communicate to the horse by naturally instead of using force.
So instead of getting your horse out of the pasture and putting the saddle on, lunging for a few minutes then getting up to go on a trail ride is not good and to me not considered natural horsemanship.
So instead of doing it that way, you get your horse out. Tie him up loose or in a grass area while you brush him as a sort of reward and relaxing moment so he looks more forward to seeing you because he knows he will get to eat the nice grass! Then you groundwork him until all his focus is on you, he is listening to you, and he respects you. Then you slowly put the saddle up, nicely and in a way he knows you and him are OK. Then you put the bit on nice and easy and before you get up to ride, you walk him around or do more groundwork to get him used to the saddle and adjust.
That is only one way of doing NH. IMO
If your horse doesnt get to graze in his normal set up, then giving him some grazing time is cool, but you don't have to do that while brushing, infact, it's not so great 'cause he won't be paying attention to you at all and stuff can happen when your horse isn't paying attention to you. And many horses don't consider brushing any kind of reward. They allow me to do it because they must tolerate it. I'll be gentle, but they don't like it enough to come to me in the pasture for brushing.
A person might do some ground work, yeah. But, they might not. It depends. How does your horse feel today? I don't' mean happy or sad, but is he tense or worried about being seperated from the herd? Is he grumpy and blowing you off? Is he jumpy at every rustle of the wind? Is he lagging on the lead line?
The ground work before mounting an already trained horse would be meant to feel out where your horse is and whether he's in a good place to just saddle up and go on. If he isn't, then you might just do a few little things while leading him to the tack up area, and that might be all it takes to get his mind centered. That's ground work. Or if he's really bothered by something, you might chose to lunge him a tiny bit. You can do enough with just a 12 fool leadline (I was going to change that "fool" typo to "foot", but then I decided I kind of liked the "12 fool leadline". Might be a handy tool for groundwork!), on the halter, looking for your horse to follow the leadline and the cues from your body. Done.
And though you might be soft in putting a saddle on, you don't *****foot around with the tack. If the horse needs to sniff it, h m m m. ... must be a fairly green to tack horse. Otherwise, he shouldn't care one bit. If he does, and he's jumpy, then maybe you need to do groundwork but most of the time there should be no need. And same with the bridle. Those things are part of any kind of horsemanship.