I did draw it crooked, but I just scribbled on the chart in a hurry to highlight the things I was talking about. Wasn't going for "perfection". Trend lines are purely conceptual and do not actually exist in the real world, so there's no right or wrong way to draw one. You simply draw them to help yourself understand a chart or demonstrate something to others.

There are lots of different opinions on how to trade, how to do TA, how to do FA, how to scale positions, how to manage risk, how to allocate assets, etc... Two money-managers with opposing views can often be successful in the same market (seen it many times). Someone like deathcode might be successful this year by merely holding his coins and adding to his position, whilst I might simultaneously be successful buying the dips and selling the rips.

EDIT ::

As a general rule of thumb, however, you only want to add to your positions during substantial dips, to keep your average unit cost low...