if I speak three things I think that is too much, I just give advice on things that don't need to be done when bitcoin prices go down, don't panic sell and sell bitcoin at low prices so stay stay on bitcoin and arrive at the highest price.
This is really the thing that must be done. Do not sell during the market on red state, or when it is down, probably hodl and wait for the time when the market turns green or rise again the value. Then it is the perfect time to earn money. Being smart is indeed needed for the bitcoin 's market.
But someone's smart way of thinking is very different, you cannot force others to follow what you have mentioned. The mindset of graph price are different between me and you and others in this forum. As what you said, never sell when prices declined.
But for me, I will see the cause of the price reduction be it technically and fundamentally. I will continue to hold when the price decreases if the cause of the declining price won't have a large effect on the market, in general the coin price will return to its original price. However, if the cause of the price will give a big impact on the decline price then I would sell my coin and certaintly will return if the price is at the bottom.