Okay, so, let's make some shears. You don't need a crafting table for this one, actually. It's only two spaces. So, you just need two iron ingots, and you put them diagonally to each other like that. And then you've got yourself some shears. Where did they just go? There they are.
So, once you have them, you can just click on some leaves, and that'll let you actually collect leaf blocks as you can see, instead of just destroying them. This actually works on a bunch of other stuff like, grass and vines and whatever else. And also, I don't have any in front of me, but if you see a mooshroom, which is a cow with mushrooms on it or a sheep, you can shear them too. Shearing a mooshroom will get you some mushrooms and it'll turn the cow into a normal cow. And shearing sheep will get you a bunch of wool without killing the sheep, not like the old days when you had to punch them. Anyway, that is how you make shears and use them.