@OP the top of the list that should be avoided is overspending. No matter how a person applies all the knowledge about acquiring wealth, and is circled with lots of rich people if he can't manage his acquired wealth properly, he won't become/stay rich.
Overspending will exhaust the person's accumulated wealth easily especially if he spends more than what he acquires monthly. Between the person who procrastinates but knows how to spend his earnings wisely and the person who does not but overspends each time he receives his paycheck, I am sure that the person who procrastinates will be way richer than the one who does not. I am not saying procrastination is a good thing but this simply show the severity of overspending over other factors that kept us from gaining and preserving wealth.
So I think before mentioning other things to avoid, the person who aims to gain wealth and become rich must first understand that overspending should be the first one to avoid.
Getting rich is not generally about luck, though luck plays a role but hardwork plays a bigger role, self motivation, discipline, risk taking and many others still got their roles to play for one to acquire wealth, according to a research I made, it says to become rich one has to learn, earn, spend wisely, invest and also avoid being in debt too often so I put it to you that there are rules to becoming rich.
Imagine someone earn $10K per month and he saves $1K every month. After 10 years now he have $144K, he choose to resign and open a business with all of his savings, he's working hard for 3 years to make his business to survive, but he ended up bankrupt.
The guy has being discipline for 13 years, taking risk to open business and hard work, yet he didn't get rich.
In this story, I think the fault lies on the person who established his business. There may be some gap on his decision or possibly, his skill is not inline with the business he opened. There are lots of possibilities but I think it is more on the connection, skills, and choice of people around him. Critical thinking and making decision on each situation are also important. There are lots of factors that contribute to a business's success like strategic planning, proper financial management, good service and product quality, etc.. and missing some of them can lead to bankruptcy.
Being rich doesn't mean you have to work hard, but it's more on you have to work smartly so you can take advantage every opportunity that comes in front of you. While taking risk is the first thing to do, however learn to take things at your own risk. Know your limits and your potentials so you won't keep beating around the bush but go straight to the point where your goal is.
In order to work smart you must work hard because if you have experience in something you mastered, you will know how to solve it quicker than before. Taking every opportunity require you to work hard since you need to spend more time than before.
I think in order for working smart to take effect, it should be coupled with working hard. Working hard and working smart are two different things, they can produce a synergized effect if combined.