I use a diamond dust stone for my chef knives. I aim to keep a thin edge on them with an angle to the stone at about 30 degrees. That gives a clean sharp edge that works the products nicely. If you are going to use the blade for hard or abrasive cutting then you can use an angle of 45 degrees (the default angle for many knives), but it will hold the edge slightly longer but not be as sharp to begin with. The 45 degrees default angle that comes on many knives needs to be worked down to 30 if the knife is new. Just do it gradually each time you sharpen it, or get into it with a coarse stone until you get the 30 deg.
You do not need to lubricate a diamond stone but a regular rinse in soapy water helps get the accumulated metal off the working surface.
If you use any other stone then you do need to lubricate it. I prefer to use soapy water, not oil. But you need to keep the water up to the working, it helps keep the pores open on the stone and hence cutting the metal in the blade, if the stone gets clagged, then you are just polishing the blade.
Butchers steels are popular with some and shunned by others, Butchers love them (especially the diamond ones). Chefs are divided, I dont like them for kitchen use other than when I am using cheap knives in rushed situations. Such as when we worked as chefs on a russian cruise ship in Antarctica, we shared the galley with the crews chefs and they are brutal on knives. They give them to the Bosun who used the bench grinder to sharpen them
. We soon found it was better to hide the good knives in our room & then use cheapies and the butchers steel.
As for sharpening techniques. Angle the blade and concentrate more on drawing the blade along the stone trying to start at one corner with the tip working down the blade until you reach the other corner of the stone. Takes time to master well, but that is like any skill worth learning. Others like to work against the blade, or do circles
.
Ciao