wall only block placement (TUTORIAL)

So I had seen a bunch of forums regarding this topic, but half of them had no answer and the other half linked to NorthWestTrees torch placement video. I wanted to simplify it and provide my own answer, because I solved it.

first off, make sure that your block is set to Y axis rotation (FROM BLOCK FACE) this is important so that you don't end up placing the leaves on, for example, the wrong side of the block when looking at a block from an odd direction.

Next, here is the procedure I used. It goes under the "block valid placement condition" section. This procedure is ONLY for the sides of the block, and not top and bottom. I hope this helps anyone struggling with this!