Thank you Declan. So to try sum it up in simple terms (for me) I would be best setting out the building with the block on edge. I then fall back and put the blocks on flat behind this. This will give me my first course.
Then for my second course I build the block on flat over the block on edge and then put block on edge in behind the block on flat. I continue this trend until desired height.
Regarding corners, when building block on flat or block on edge, I just bond as normal keeping half bond?
And hopefully my last question on this - do the perps / cross joints of block on edge and block on flat have to align on each course? For example, should the first course of block on edge cross joint / perp but in line with the cross joint / perp of the block on flat?
Or am I now overthinking it?