Having worked in a pig plant, and owning the Razor's Edge sharpenign kit, I have a bit of experience with steels.
First of all, a steel doesn't actaully sharpen a knife. Sharpening removes steel, while a "steel" aligns the edge. When you use a knife the edge usually bends out of place before to wears away, so steeling re-aligns the edge! Cool eh!
A smooth steel is better than a ridged one. Steels with ridges on them are rough on an edge and although they do work, you will destroy your edge faster.
As far as technique goes, the KISS method is to hold the steel vertical, such as resting the tip on a table so that the steel is pointing straight up. Then stroke your knife on both sides of the steel at an angle slightly larger than the sharpenign angle, and do it lightly. 5-10 times per side ought to do it. I have heard that steeling can weaken an edge over time, and I believe this is correct. But, with daily steeling of my folders I have been able to go waaayyyy longer between sharpenings.
keys in your technique are keeping the same angle on both sides, golightly, not too many strokes and don't bank your knife on the steel. A light stroke realigns the edge, so if your blade hits the steel roughly, it won't so it any good.
P.S., for a great steel, check out Razor Edge Systems folding steel!
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