Making Kamma. Kamma comes from our actions, our speech and our thoughts; all three make Kamma. They make the conditions that something will happen later due to what we did. Kamma is what we did. Now what comes is the result of Kamma, our past Kamma. We make Kamma through our thoughts, our speech and our actions.
Where does it start? For any one of these three, thoughts, speech and actions, it starts in our mind, it starts with a thought. We don't get a single word out unless we have a thought first. Even when a person is frightened and they scream, they still had a thought first. You don't get a single word out unless you have a thought, and you don't do a single action unless you had a thought, also (excluding the natural processes of the body such as passing wind, etc.). Otherwise you don't do a single action without having a thought first.
So all of your Kamma actually originates as a thought, you've got an intention there. That's the most important part of your Kamma. Because the intention creates the Kammic result to begin with, you can make it worse or better by adding speech and action. But it's created in the beginning.
Now sometimes our action may look like making bad Kamma, but if the intention was actually good, then the intention makes Kamma. So in this particular sense "intention makes Kamma" sometimes our actions, sometimes our speech, they don't look right. Somebody may say, "Oh no, that person is doing something wrong". However, if the intention is a wise intention, then that's what makes the Kamma.
A little example is training a dog. My father-in-law was training a dog by hitting its face with a newspaper every time the dog barked at a cat. It was not his first dog, he had it for three years but somebody else had it before that, and the other guy had trained the dog to bark at cats. My father-in-law wouldn't allow this, out of Compassion for the dog, for the cat and for his arm, which got yanked every time a cat ran by. He trained the dog to not bark at cats by hitting it on the face with a rolled up newspaper. Yet somebody seeing this without knowing the background, might think he is beating a dog. After a while the dog quickly understood. Hitting it on the face with a rolled up newspaper doesn't actually hurt the dog. It didn't take them very long before, when walking along with my father-in-law, if the dog saw a cat and looked the other way. So this is it, the intention was purely out of Compassion, although the action might make someone think he was hitting the dog. No, so this is where intention is the key to making all Kamma.