Just got finished doing two of my hens. It's important to keep an eye on toe nails, especially those on older chickens that may be far less active than they used to be. The toe nails, if not constantly worn down from scratching in the soil, can become dangerously long and some can even curve around and affect the ability to walk normally.
I use a dog/cat nail trimmer, and I snip very little bits at a time to avoid hitting the quick. Watch for a dark "dot" to appear. Cutting beyond that will result in a tiny red drop of blood, signally you've gone a bit too far. Dab a bit of cornstarch on it to stop the bleeding.