Really if your birds are active, with good bright eyes, curious about the world, eating and laying well, that is a big part of overall health. Now about this time of year, they can get looking a bit rough as they go into molt, but mine always still eat well and move easily.
If you see worms, or bugs, well then you need to do something. However, I seldom handle mine. I just like to watch chickens. If you do need to catch one, there are a couple of ways to do it. A chicken hook is what I use, and really it will catch them so fast, and you have them in your arms, the rest of the flock does not hardly notice.
I have also heard of taking a piece of chicken wire, and making a tube out of it. Drop it straight down over the top of the chicken, and they are contained, again with little fuss.
I have used a fish net, works well for separating fighting roosters, but to be honest, it really upsets the rest of the flock.
And of course, looking at night is the easiest.
Mrs K