First, you don't have to be meticulous about removing every bit of stem from fresh, tender-stemmed leafy herbs like parsley, cilantro, basil and dill. I am always amazed at how much effort my students put into this. If you are ever in doubt, taste one of the stems–if it has the same flavor as the leaf and will be the same texture when chopped, then use it!
When working with herbs with woody stems like rosemary, sage, mint, and mature thyme, hold the top of the stem in one hand and strip the leaves down (in the opposite direction from which they grow) with the other. Place the washed, dried leaves in a tight pile and, keeping the point of your chef's knife on the board, rock the end of the blade closest to the handle up and down over the pile. (Watch our video on How to Slice Fresh Basil.)
Or, for a super easy way to more coarsely chop fresh herbs, you can use the "stuff and snip" method. Simply stuff the leaves into a glass measuring cup, and then use kitchen shears to snip the leaves. Just be sure to rotate the shears as you snip to ensure that all leaves are cut.