I have quit taking the tiny lower branches on Seedlings mainly, I've found they grow small even when they have established after being cloned. You want to take healthy branches ideally when the plant is healthy and vibrant. I usually go up a couple node sets for my clones but as others said take the whole branch then cut it down to size of your liking.
Always have a cup of plain water in a secure spot when cutting clones and once you cut them drop them into the water until your ready to touch them up and root gel them.