For manual trading - price action on the 4 hour charts (and small/thin bars to get a broad historical view of the movement). Humans can process price action, judge support and resistance, weigh up fundamental news and have 'gut feel'.
When developing automated traders, indicators need to be used. What manual trading lacks automated trading is strong in (unemotional, strict rule adherance, historical testing, 24/5 operation) and what autotrading lacks manual trading is strong in (whole view, complex price action patterns which humans can view with experience easily, fundamental news influence, gut feeling).
One is not better than the other, but one may be better for you. I/we trade almost exclusively automated. My weakness is emotion. For others who have the manual trading gift, it is the opposite. Manual trading requires a lot of self training in not only reading graphs but coping with the emotions of trading. Automated trading requires a lot of system development (training).
Each requires a lot of effort to do successfully. 95% of forex traders lose money. It is said 10,000 hours of practice is required to become an expert. Neither is easy. If you're one of the 5% congratulations