I found that the easiest way for me to mess up isn't misreading the direction, but having the wrong "gear ratio" for my position: when spot prices go up, I want to add more; when there's a slight pullback, I want to run; futures are even more ridiculous, with leverage ramping up, the liquidation line feels like it's right in your face, and your mindset gets pushed around.

Thinking about it later, it's pretty funny.
To put it simply: it's one sentence—first, determine the maximum loss you can tolerate, then decide how much to buy, rather than the other way around.
Now I cut my positions smaller, leave enough margin as a buffer, and would rather earn less than get stuck by a single needle that jams the whole machine.
Recently, everyone keeps interpreting ETF capital flows, US stock risk appetite, and crypto prices as interconnected, but I also look at that, though at most as background noise.
When it comes to placing orders, the parameters and stop-loss levels are more reliable than emotions.