I would definitely recommend that. I did that with my goats when I first got them and turned out to be puppy dogs. With my boys, I'll just go sit out in their paddock either with my camera or my phone. They get really curious and will walk up to you, sniff you, mess with your hair. My boys have a tendency to investigate, walk off, then come back and graze nearby while "keeping an eye" on me.
If you're working with a non-trusting horse, ignore them if they come up to. This reinforces that a human presence doesn't always mean work or physical contact. If you have a horse like my boys, I pet them all over while I'm sitting there and they eat up the attention. But again, sitting down in the middle of two horses is usually not a good idea.
I would advise sitting in a chair. I trust my horses enough to not trample me, and can get them to back with a verbal cue if they're getting too much into my space. So when you're working with a new horse, pull up a chair, find something to keep yourself occupied, and ignore that horse!