How to trade the magical trend lines ?

From new traders to experienced traders, the most under valued technical tool is trend line. Since everybody thinks its easy to draw the trend line, they dont give much attention to it.
I have connected A & B to draw the trend line 2 weeks before. When I analysed for this week's move, I just extended the same trend line and it is marked as dotted yellow line. Price tested the trend line at C, and D. So how this trend line became magical ? The support drawn in blue dotted line & the yellow dotted line is broken at E. The confluence zone at E made the trend line as magical and the fall became non stop.
It is very useful in multi time frame analysis too.
Simple analysis holds the power.
Simple analysis makes the trading execution easy.
Check yourself and see whether you are drawing trend lines or magical trend lines.