in my humble opinion, Fibonacci is nothing more than another tool to measure or calculate the movement of the price. If you use it alone can be totally ineffective or very risky. However, if you use it as a support for price action along with instruments that measure momentum, volatility…, then, Fibos can be very helpful. For me, Bollinger Bands, Candlestick formations, RSI and S/R are the best tools to use. This is just MY opinion.
However, I think that what it really works is to repeat blindly once and again “a system” that fits your personality, a system with which you fell comfortable.