I just completed an evocation of Zadkal. Again, no physical manifestation, but I think he showed up.
I drew the square of his kingdom and his sigil, then lit the candles and started meditating for focus. After I felt sufficiently focused, I did the banishing from the book then traced the triangle with a ritual dagger, pronouncing it as the platform in which the spirit is to appear.
Following that I traced the Circle and went back to my chair to meditate to refocus. I then opened the square of the kingdom using the gateway incantation found in the book and the "gaze until you see the figures disappear and reappear" thing described both here and in Works of Darkness. After I felt it was open, I placed it in the small circle in the middle of the triangle and went on to do the same for the sigil.
Next I sat cross-legged in the circle and gazed at the triangle. I actually thought I saw a shadowy shape vaguely appear but it disappeared finally and didn't come back. I finally saw some shimmering and uttered the sentence of evocation (as I was saying it, I felt a strange coldness in my chest), then proceeded to funnel my chi into the triangle. I vaguely saw the indistinct shimmering shape of two feet in the small circle after a while and continued pouring chi in, but it didn't get much better, there was the same vague shimmering up till just below the knees. I then told the spirit to answer me truthfully and obey my commands faithfully (again coldness). Then I meditated a while and poured more chi, after which I uttered my request.
I started off by saying I wanted him to either provide me with a familiar or a direct gift to increase my ability to absorb knowledge about the arts and sciences, then for a while, my mind went blank, I felt gripped by wonder. I then continued on semi-coherently about doing it within the week, preferably in the next few hours as soon as he went back to his kingdom, in my sleep. I continued with this daze for a while, asking that his familiar help me with discipline as well.
Finally as I dismissed him, I felt energized and focused again. I said the final banishing and turned on the lights.
I folded up the sigil and put it in a drawer.