I always thought that people who are actually losing a lot from trading is because they come into the market unprepared and just jump into trading because of their greed to get instant profits. Though they actually know that trading is risky, but maybe some just need to experience the risk of losing first before they can actually say that yes, trading is risky and certainly never that easy to make profits.
One thing is certain for those who want to start trading: they have one common aim, which is to make a steady income from trading, even if the earning is not too steady, but semi-steady is also a good one. Perhaps no body goes into trading with only the purpose of making losses all the time. Leaning toward perfection is always the first aim for some people before "making profit" becomes another aim, which I can say should be the second aim. The only mistake some people make is that they don't have that desire to learn and become perfect first before making profit, which should be their sole aim; they just conceive the thought of making profit without having a second thought of how difficult it could become to learn and master the trading tools.
But I will say that everyone who is going into trading has one purpose in common, which is to make profit. Even some traders, despite their experience and high skill in trading, still count losses, so anyone who jumps into trading with just that feeling of making profit quickly will have to tell the story of what their experience will look like.
In the past, I watched a series of trading videos on YouTube, and in these tutorials, they sometimes don't make those tutorials with a real account, but just visual trading and also some kind of demo account, and the worst of it is that when they trade, they don't show losses; they only show how much profit they have made and how you can make that profit. I have tried some of those tutorials, but I have seen that some of their strategies don't work for me.
OP, based on your questions on how to minimize loss, I think one case is to not just watch a video tutorial online where the teacher has shown you how they make $1000 in two days with a particular strategy, and the person watching would just believe it's true and just go ahead to put in huge capital and enter the trade with same strategy. As a trader, when you watch a trading tutorial online, the right thing to do is to put in the minimum amount you can afford to lose and try out the strategy or the trading tool combinations. Otherwise, if you put a huge amount at once just after watching the video, well, let experience tell the results.