There's an entire history of technique that is collectively termed technical analysis. Names like Dow, Gann, Elliott, Wilder, Wyckoff, Ehlers, and a hundred more.
TA is a part of markets just like futures, options, stocks, and bonds are a part of markets. It's a way to learn the language of trading. That language is key.
Rally, break, swing, consolidation, reversal, trend, channel, volatility or all of the various candle terminology (I don't even know them). Knowing the lingo is a huge part of gaining any real skill.
Most of it's useless, but some of the best ideas are also in there. Detrending, relative volatility, price action, and volume stuff.
Personally, the best thing I've found is something I made using a bunch of ideas from TA and some higher level math and finance stuff.
It uses a regression differential spread against a smoothed price lag.