Yarrow Stalks
Yarrow stalks are the oldest method. You use forty-nine stalks, which you divide and count in several steps, repeated for each line. Six lines, from the bottom up, complete the hexagram.
The process is slow and ceremonial, and its odds are not the odds of the coins. With stalks, the changing yang (9) comes up somewhat more often than with coins, and the changing yin (6) comes up far less often. For this reason, readings with stalks tend to change more from yang than from yin.
Here you do not have to count stalks: the site simulates their odds without the ceremony. Ask your question, generate the six lines, and notice the changing ones, because they carry their own text. If you want to perform the ritual for real, use the manual method and mark the result here.