Here is the "rest of the story"
You obviously have the "get it sharp" part of honing down, now comes the next step getting it even....
Very few razors out there have a perfectly flat, even, bevel to sharpen, there are some, but most have a slight off spot, the X stroke and variations of that stroke are what "pulls" those spots in to line... Now in some cases you have to use small circles, or some light Japanese style strokes, to pull certain areas into line, and then go back to the X stroke to smooth that up.... All this should occur at 4k or below, the 4k stone should be the last of the "sharpening" process after that you are just smoothing and refining that nice, even, sharp edge you have created.....