The thing about technical analysis is it is just as much a science as it is an art. To answer your question, I would say both.

Sometime if have a good high or low to start a trendline off of then I will use it, otherwise I try to draw of the main point of each top of bottom with the line hitting some wicks and some closing prices along the way.

You can sort of see what I am talking about in the descending triangle example above.

This holds true with support and resistance lines as well. It's not the exact price where the line is but the area of it we expect price to have something happen.

If you are free at 4pm EDT time on Tuesday's I do the scaredycat investor show on MSPWaves and do a crypto charting segment each show.