How would you change the H-R Diagram so it would be easier to read?

Answer 1

Not quite sure what you mean by "change", since H-R diagrams are done in a wide variety of styles and formats. I always appreciate it when they put more than one scale along the x-axis, since you see H-R diagrams with spectral class, B-V, or color temperature as the abscissa, making them sometimes hard to compare.