The worst habit is not to learn. Learn on mistakes, learn on losses, learn on successful trades. Trading is all about learning and consistent learning. Traders should understand that without learning they would never be able to develop their skills and receiv knowledge and experience, hence it's a mandatory thing. Moreover, risk management practices neglection is also a bad mistake and habit. Traders think that they would certainly win the position without compliance with the risk levels. It's wrong and if you are such a trader then you will certainly faced losses because of this reason. So, be careful.
Indeed most novice traders when they find forex as a money-making machine, assume trading is a short term way to get earning, hope fast money in forex is only a dream, sometimes dream still unrealistic, different from reality, before they have a high dream, better wake up and learn how to achieve the dream.
It is a wrong mindset when newbies come to forex with such a mindset, forex trading is only for those who have specialized skills to expertise profitable trading strategy, and sometimes trader needs long years to achieve good level trader.
Revenge is not good to make recovery after losing trades, because get loss decreases balance and margin strength reduced, revenge with an open double volume position size just leads to making a quicker loss usually.
I read about the habits, some of which I have. About my passion for trading, I had such a habit from the beginning of my Forex activity for about three years, I was ready to trade night and day. And now it depends, if everything is good, I don't want to get distracted from trading, but there are days when I don't feel like trading, I don't even want to go near the terminal, especially when there are no serious market movements or after a sensible loss.
In my opinion, switching timeframes is the worst trader's habit, though many would not agree with me. There are so many variants on charts and switching of timeframes takes place after opening a deal. A trader is looking for a price reversal. I had it that way before, but I got rid of it.