Trade too much - You don't have to enter a trade everyday even if you're a day trader.
Trading too much will create a kind of poor mindset that can expose traders to high risk.
Trade randomly - Don't trade every coin. Be smart, choose coins you're comfortable with. Don't gamble, always have a plan and follow through on it.
Trading better coins will be the best, number one of them is bitcoin. Some coins are just not good while may coins are shitcoins, shitcoins that people will trade but keep losing.
No stop loss: This happened to me once. I lost a chunk of my capital. Stop loss was created for a purpose use it for every one of your trade.
This depends, and also depending on the analyses. If it is spot trading, there are may times there will be correction, and after the correction is bullrun again. Stop loss can help but it has its own downside too.
And in addition to what you just said dude, if anyone will become greedy in doing trade activity due to aiming to earn big in a fastest way, will surely lead them into nothing but losing their money in the end. Then, the next one is lack of discipline for themselves, because with this it can destroy our good mind condition, mindset, and our good plan as well in the end to get a nice profit into trading.