What are common mistakes that new or inexperienced managers make?

I thought the question was aimed at new to the role not necessarily new to the team?

I found the advice about visibility pretty on the nose. I have yet to have a direct supervisor who hasn't stolen credit a few times. In contrast the guys or girls above them have all been really good at directing it downward. As far as my career has gone anyway.

When I first started work out of college I kept a notebook of "things I like/don't like" about my managers, mostly as a training piece for myself. One of the top qualities one of my managers had was his comfort level with admitting to me "I don't know the answer to that, but I think I know where we can find it".

Probably summed up as something like "check your ego at the door". This goes for not only managers, but any member of an organization -- pretending to know something when you really don't and being afraid to ask questions is a huge red flag to me for both managers and employees alike.

And back to the list, IMO that's a pretty good list, especially coming from one person's experiences.

I surely agree with most of what's posted there - a majority of it is straightforward common sense that's barely even specific to management.

"Don't procrastinate, communicate clearly" are to management what "eat less, exercise" is to losing weight or "only buy things you need, spend less than you earn" is to saving money.

The problem isn't managers that they haven't read this compilation of checklists or its equivalent in any of the thousands of management books out there.

The problem is the brokenness of management as a role in general.

Too many organizations are stuck in an broken structure which makes management the most direct if not only way to advance in terms of status, pay, autonomy or all three.

The end result are incompetent managers who need to be taught common sense or unhappy ones who are far better suited to other roles, but recognize them as dead-ends.

If becoming a manager stops being desirable for all the wrong reasons you won't have to remind your new, inexperienced managers not to be lazy or not to manage by intimidation.

So at one point I took on a management job, stepping up from a (lead) developer. I felt like the whole thing was kind of a train wreck and I am still slowly analyzing the black box recordings from it. This was my first time having direct reports that were not one or two interns and managing a team of seven other highly intelligent people was quite a chore in itself. What bugged me is that I could never tell if the problem was the environment or something I was doing. I tried to be fair. I mentored people when I could help. I tried to not be overbearing when I had nothing to add. I present challenging problems to the people who I thought would find them interesting. I advocated for my guys to the upper management, trying to improve working conditions. I insisted on being flexible, discarding what was slowing us down, and adopting what was good. None of that seemed to help: my dev team learned to resent me for delivering the bad news (for example the dev team was the fallback for doing data entry for weeks on end when nobody else could handle it and we had no time to finish better data entry tools because of it), and my boss(es) learned to resent me for not delivering what they expected.

I know that there were quite a few problems above me. Lack of leadership carries far and wide and there was a disconnect between what the products did and what the management thought it did. Lack of money (think lack of compensation, lack of tools, lack of time for anything but immediate returns) did not help either. I do keep questioning whether I was doing all the wrong things or if I was put in a situation designed for me to fail, or perhaps both.

After I left I understand the company hired three different people to replace me: a manager, a dev lead, and a support engineer. I suppose that's some kind of a sign that I was trying to do too many things at once. Most of the engineering team also left after I did. The least I could do is give them the great recommendations they all deserved so all of them moved onto exciting new pastures. However, I cannot help but feel like I failed at this task that I felt sure I could tackle and I don't understand why.

Please excuse the rant. These types of topics always trigger those same feelings in me.

Edit: now I work as a developer on 2-3 person teams. I have no reports. I get to be productive again! I can write code that doesn't have to suck to compensate for poorly chosen deadlines. This is good for the soul. I do miss leading a team though; not managing but really leading. One of my proudest moments was when I was allowed to follow a system of estimates and sprints I put together and for 8 weeks my team delivered on schedule and exactly what was promised. That was one of my more joyful moments.

Piecemeal advice, even if you know the answer to all job interview questions answering a straight up "no haven't dealt with that before but I'd tackle it by learning x y z." Will set you apart from pretty much everyone. Being able to confidently tell someone you politely have no fucking clue is pretty rare in my experience.

Example I interviewed for a job I know I was qualified for, they kept asking questions about things I really had no idea about (all stuff I had never dealt with before - only similar things) they were so refreshed by the honesty and how I dealt with not knowing things they offered me the job despite pretty much what I thought at the time was tanking the interview.