I can't begin to tell you the number of times I lost money to forex because of a bad trendline when analysing the market make sure you draw a precise and accurate trendline to avoid incorrect analysing
Learn from my mistakes
The mastery of how to draw trend lines and then spot supports and resistance are parts of the basics of trading, and it is a part of the things that any new trader needs to know and master before progressing into the intermediate stage of learning. If a trader skips learning how to draw trend lines to see if it is an upward or downward trend, or how to spot resistance and support, that trader will experience difficulty in understanding and will continue to make losses until they go back to learn that basic knowledge.
It is an important knowledge.