Had my eye on this design for a long time.
Got a nice yarn for it.

Adjusted needle, CO and rows for my gauge.
Math.
Never my strong suit.
I placed the linear accents as written for the first section, then, in various places (left, right) along the way.
Elected to do some striping in color change areas of main section.

Recommendation:
Measure out all the yarn segments needed for the tassels and vertical accents ahead of knitting the scarf. In so doing, the scarf can be worked up with all remaining yarn.