Single Bevel Sharpening
There's no right or wrong answer to how you want to go about the initial sharpening and bevel shaping and subsequent edge maintenance to your knife, I will discuss here what I do....
My way on the initial sharpening is to first make sure the back side is good to go by flattening it using a 1k(ish) stone. I'm using very light pressure to make sure that this zero degree bevel extends to the cutting edge and nothing more. I do this because almost every new knife will come with a buffed bevel cut at a higher degree than zero - we must erase this and create the flat zero degree bevel or else your polishing stones will never touch the cutting edge. I'll then follow this 1k stone to polish when I do the front side later on.
Now I flip the knife over and cut my edge in using the same 1k stone. I cut this bevel at 1-2 degrees more obtuse than the blade road is ground. This means I lay the knife down flat on the blade road and then ever so slightly lift the spine to raise the knife off of the blade road and then sharpen the edge. This does two things, first it ensures that I've created a burr (in other words - an edge) and second it removes the often found obtuse factory edge. All I need to do is to grind a few millimeters in height at this angle and I'm good.
Next I flatten the blade road using a stone normally between 120x -500x. I start with the blade road sitting flat on the stone and if everything goes correctly I'm grinding up to the shinogi line at the same time I'm headed down to the edge. Most often I hit the shinogi line just as I'm hitting the top of the edge bevel that I cut in using the 1k stone in the previous step. Once I've made the blade road even so that along it's length it is one even grit pattern from heal to tip and shinogi line to my 1k edge I stop. I will do a bit more to get the blade road to extend down (just) into the 1k edge because this is important to what I do later.
Then I move onto a finer stone (like the King 800x). I use this for just a minute to even out the appearance of the two bevels to make them look the same grit level. I work the blade road first and then, while still moving, I raise the spine to remove the blade road from the stone to hit the cutting edge bevel (previously cut with a 1k edge). Once it all looks even as one large bevel I'm finsihed with this stone.
I follow with a finer stone (like an aoto), first honing the flat zero degree bevel on the back side and then working the blade road and edge bevel exactly as I did with the 800x stone, again stopping when it appears as if they're one smooth bevel. The point in working both the 800x and aoto in this manner is to blend the two bevels together. In working them the way that I do I create a hamaguriba (clamshell/convex) shape at their union.
Now it's time to polish...
First up is to work the back side zero degree bevel using a polishing stone 6k-10k. I'm looking to put the keenest slicing edge that I can on a yanigba where all other single bevels benefit more from a slightly toothier edge. Choose your finishing stone based on your application/needs.
Then using the same stone it's onto the front side, to the cutting edge.
Most often I isolate the cutting edge again at this point (just like I did at the beginning with the 1k) and hit just this bevel - seperate from the blade road bevel. If you just hit the edge bevel you're done, if you hit the entire blade road you need to then go back over the blade (ONLY) with the aoto again to make it look pretty. This extra work does look sweet when done correctly but it's just for looks really, not much other benefit...although on some cladding it can add a level of slipperyness to the surface texture, much like what can be achieved through the use of natural stones. It makes for a shiny matte finish - make sense?
Next up is stropping...
For most all single bevel knives I'm using felt and diamond spray today. I like what this adds to the edge but for a knife like a yanagi I'm looking (again) for a smooth slicer so I'll use the felt/diamond but I follow it with felt loaded with 0.3 micron chromium oxide. The edge becomes "softer" because of the effects yielded by round particles of the chromium (versus the blocky coarser structure of the diamond particles).
If everything has been done right to this point I've now got a 98-99% flat blade road with a hamaguriba shaped edge. I've added edge strength by increasing the blade road angle and at the same time I've reduced the amount of friction by rounding the transition between blade road and edge bevel and I've also increased the edge strength by using a convex grind. The texture should be somewhat slippery when wet to aid in non-sticking and food release.
For future touch ups it would be recommended to use felt/diamond and felt/chromium oxide and when that doesn't work it's back to the polishing stone, both front and back, (but only) hitting the front side edge bevel - not the whole blade road. Then back to the strops.
Eventually this won't work that great and then it'd be advised to go back to the aoto where you work both sides again and then back up through the polishing stones and strops. Of course after that it's time to start all over again with the 1k although it's important to note that if at all possible all back side zero degree work should be (after initial sharpening) preformed with polishing stones only. Keeping the wear to a minimum to the backside (ura) is critical to the lifespan of these knives.
I believe my way of doing this offers a good way to get max performance, ease of sharpening, and good bevel/shinogi correction over time.
Hope this helps...