@faonshi it helps to print the pattern first, then you can draw the triangle for the shaped start where it cuts into the pattern and keep track of the string order on the diagonal. There's a video on #10388 that shows how.
Since the strings are not symmetrical, you can fold double-length colors so they hook around each other in the center, then same colors will end up on the same side.
You'll also have to add a couple single strings in the loop as well, since this pattern has an odd number of colors for A and C. Just place them with the other strings and knot around them all as you would normally when forming the loop. Then before starting the pattern, carefully pull those single strings through so the end gets hidden inside the loop, and be careful with your first knots so you don't pull the single strings all the way out. 😊