If you could use only 1 Tool/Indicator for the rest of your life? which one?

[Zilon]

Fibonacci is a nice indicator but the market volatility will not permit me to use just indicators to get the best out of the trend. I have only tried a few indicators which include RSI, SMA and ECDA in which ECDA is my favourite indicator but one thing i don't do is using indicators alone i add  candle stick chart patterns to my indicators and it gives me more advantage.

[Woodie]

Me personally would use Fibonacci retracement, how bout you?

Fibonacci is a good tool and if I were to use it, it would help me the the premium and discount levels and the alike , otherwise my trading strategy allows me to trade with a naked chart and I will do this with a smile on my face.
Btw I thought trading these days has moved away from support & resistance, moving averages and all these indicators and traders are more of the ICT and smart money concepts these days