I want to be clear here (and possibly clear up some misconceptions). A steel will keep a knife sharp. A steel will do nothing for a mostly or very dull knife. A steel DOES NOT sharpen knives. If you have a sharp knife and properly use a steel every time you use that knife, it will remain properly sharp 2 - 3 times longer than if you don't use a steel. This is, of course, a generalization and is variable depending on how much and how properly you use your knives, but it gives you an idea of the benefits of using a steel.
Note: I wouldn't recommend using a steel on serrated knives, especially the cheap knives with very small serrations (the 'miracle knives' that are on infomercials).
Step 1: Why It Works
The first is a sharp knife, this is what we're trying to maintain.
The second is a truly dull knife. Using a steel on this edge will do nothing - you're wasting your time.
The third is a 'dulling' knife with the edge rolled over to one side; the very tip of the cutting edge deformed by normal use (even just a few cuts can do this). After using a steel on this edge, the nice cutting edge of the sharp knife will be re-gained. If not righted, the knife with an edge like this one will continue to deform and pretty soon you'll have a dull knife. NOTE: Because it's so small, you can't really see this deformation. Just because you don't see the edge of your knife deforming in this fashion doesn't mean it's not happening!
Step 2: The Stance
Stand with the knife and steel in your hands, crossing in front of you.
Because it's comfortable, I have the steel at a bit of an angle (it's not horizontal).
Hold the knife so it's comfortable in your hand - you can also see that my thumb is on the blade of the knife (which isn't necessarily how I hold the knife when cutting).
Also - I'm left handed. Keep the knife in your dominant hand and the steel in the other.
Step 3: The Motion(s)
Put the knife on the other side of the steel so that the other side of the edge is on the steel and repeat the motion.
Repeat this motion 3 - 5 times per side, alternating sides each time.
Step 4: The Angles
Step 5: Pressure, Speed
1) There's not much force here!! The amount of force that you're applying to the knife towards the steel is approximately that of picking up a normal mug full of coffee or less - which isn't very much!! If you try to muscle the knife against the steel, you could damage your knife, the steel, or worst of all cut yourself.
2) Equivalently, don't feel like you're really pulling the knife along the edge (the direction of the small arrow). You're just kinda sliding it. I'd say it's like petting a cat!
3) Don't go fast! Just because the people that you've seen using a steel probably do it rapidly doesn't mean it has to be fast to be effective. Start slow. After you're familiar with the motions, you can speed it up if you want.
Step 6: Put It Together
Step 7: Using Your Wrist
For something like a 6" knife, just use a linear motion (little or no wrist). For something like a giant 16" watermelon knife I'd use a lot of wrist.
Let me explain the video:
I'm first using a little boning knife, so the motion is pretty linear - drawing the entirety of the blade against the steel in a straight motion.
Then I grab a larger knife and continue using the essentially linear motion. Because the camera is over my shoulder, you can't really see but my hand (and the knife therein) is finishing right next to the left hand side of my torso, which isn't where I want a razor sharp knife to be.
Then I use more wrist. You can see that at the end of the stroke across the steel the tip of the knife is pointing towards me and close the to hilt of the steel, about a foot in front of my body. Much safer!
The last two strokes are one again without wrist (linear), and the last stroke uses the wrist.
Step 8: Use a Steel!!
I should mention - just like boning out a leg of lamb or cutting up a chicken, everyone does it differently. Different motions, different angles, different stances, different everything. This is how I've kept my knives sharp working at a proper butcher shop (Ver Brugge's in Rockridge, Oakland).
This Instructable was made in TechShop San Francisco; more than just sharpening knives, I make knives there! Check it out: http://www.techshop.ws/