How do you pour ganache on the top of a cake so it is smooth, yet drips over the side and hardens so quickly that it doesn't drip all the way down??
Kind of like this....
Just right temp for ganache (you have to experiment) and cold cake. as you are piping it around you kind of stop motion (keep squeezing) where you want a drip, if that makes sense. As you can see on the example cake, the sides are slightly slanted. Not necessary, but it helps.
when i put it dor drips and did not want it to go all the way I just poured less...i think I used a spoon actually so I could control how much. Also don't make it to thin...hth