many ways to draw trend line, this is one by Victor Sperandeo:
For an uptrend within the period of consideration, draw a line from the lowest low, up and to the highest minor low point preceding the highest high so that the line does not pass through prices in between the two points. Extend the line upwards past the highest high point.
For a downtrend within the period of consideration, draw a line from the highest high point to the lowest minor high point preceding the lowest low so that the line does not pass through prices in between the two high prices. Extend the line past the lowest high point downward.