I’ve been pulling out my garlic bulbs when some of the leaves are yellow and when the cloves are just pulling away from the stem. Is that right? They seem large and juicy, but I’m just checking. Also, when should I cut off the roots?
You are doing exactly the right thing!
As for cutting off the roots (and the leaves), you must wait until you have left the heads (outside in a shaded and sheltered spot on a screen, ideally) to dry until the skin becomes “papery”.
Our Gardening Tip for early August explains.