On the chart below, my Fibonacci lines are plotted from the previous day's low to the opening range (OR) high. At the open, price began to fall. It found support at the white dotted line which represents the previous day's high. The previous day's high and low can represent significant support/resistance, and when they are not incorporated into my Fibonacci lines I still watch those areas for signals.
Price fell below the white dotted line and printed a doji or hammer-type candle. It closed back above the white dotted line and I entered on a break of the doji candle (white arrow). Price rallied back above the morning high, and I adjusted my stop to just below that level.
My target was the Fibonacci extension, and price rallied to hit it at the end of the day (it actually blew threw the FE, and rallied another 50 points...but I was happy with my profit).
Note - I am working on a post about the various ways to plot your Fibonacci lines for intraday trading - I will try to get it up this week.