I'd love to see you come back and let us all know which technique works best for you.
HRT are notoriously more tricky than you'd expect, and while I've used pretty much every one of the methods mentioned above, my biggest challenge lies in being able to get absolutely consistent results when piecing many HRT blocks that need to match points.
My favorite method / tool is the tri-rec ruler. You can find youtube tutorials to walk you through the use of the ruler.