Support level, Trend lines & hidden trend lines. There's nothing really methodical about it. I personally expect a rejection here to the up side. A break through, can expect to see lows of that in 2002.
lol sorry I get you now, you could look at it from a Fibonacci fan or arc/ gann i think. hold the same principles. There's way more to Fibonacci than meats the eyes check this out you'll like this https://youtu.be/P0tLbl5LrJ8