Talking directional trading, EURUSD, and chart only, with particular reference to intraday movement. My observation is that price dynamics is the resultant of a number of technical plays going on at all time on all time scales, cooperatively or competitively. TA provides the common tool set and analytical framework. TA isn't about predicting. The movement of price is practically entirely technical.
Exploitable repeated typical price behaviors, or 'edges', come in great variety. Some of them revolve around:
Tipicity of impulse and corrective moves configurations (broadly speaking Elliot based), insufficient by itself. Deformed by other plays on all but the quietest market phases.
Relative measures in price and time (Fibo type stuff) This is a vast area of research. Some things work others don't.
Countering relatively sophisticated TA set-ups (for example set-ups built around Fibo projections)
Trendlines. Overall very useful. Some work some don't. Some stop working and then they do again. Some are created for a purpose, a few just happen.
Geometric figures. There is something of significance and not random going on about triangles and parallelograms drawn...
Configuration similitudes both direct and inverse, at different scale. (stuff that passes the random chance test)
Bar patterns. Price exhibits bars sequences that are remarkably similar in appearance. Some of them look so obvious and so artificial in nature that it makes one wonder. (at least it makes me wonder. Personally I wouldn't touch the stuff with a ten foot pole)
(plenty more I'm sure)
Useful guidelines include:
Countering extremes.
Reversion – Retrs. Inevitably price retraces. In my view most are tied to counter accumulation for a technical play. Sometimes it is more prominently a shake-out with some technical underpinning to it.
Countering retails both as in monitoring their flux and opposing easy expectations as derivable from “common sense” or simple symmetry considerations or some TA notions
Anticipatory nature. Money is in the production of signals more than in the signal itself or in its opposition. It is the work of magicians (or jokers) that produces all the wonders that simple minded folk look at.
Confluence. Of course when a number of technical reason converge in suggesting the same direction, the effects are intensified.
I believe there is no edge in common TA notions, either positively or in countering them. The game is essentially oblivious to those except perhaps when a real reversal reason coincides by chance with a silly TA one, in which case it acts as reinforcement in what to some extent must be an in-joke with traders. Of course excluding the broadest TA concepts such as trend which inevitably remains but is by itself nothing more than a concept, lacking any necessary specifics.
An ideal, allmighty tracker of all playson EURUSD would probably require dozens working on serious custom software. Then there is all that there is beyond the chart, with order flow and intermarkets and hedges and FA for long term orientations.