Becoming a manager for the first time: the 5 mistakes to avoid

This article looks back at the five most common mistakes made when stepping into a management role, with particular attention to a situation that conventional guides almost never address: managing your former colleagues after an internal promotion.

From individual contributor to manager: a change of profession, not of rank

The managerial transition is rarely what you imagine before living through it. You were effective in your role because you mastered your field and produced visible results. Managing means getting others to produce. This shift sounds simple to describe. It's hard to internalize.

In practical terms, your day changes structure. You spend less time doing and more time directing, unblocking, arbitrating. Some new managers experience this transition as a loss of meaning, because they no longer see their own output. That's understandable: the satisfaction tied to a well-finished deliverable disappears, replaced by a more diffuse satisfaction, that of seeing a team progress and make decisions without you.

Your scope also widens on a relational level. You're no longer responsible only for your own work: you're responsible for that of several people, with different profiles, motivations, and rhythms. Reading a team takes time and attention. It's a skill in its own right, not a natural extension of what you did before.

What can't be improvised is the managerial posture. It rests on the ability to calibrate your level of directiveness according to the team member and the task, and to stay consistent in your decisions over time. Contrary to what you often hear, these skills can be learned. They aren't qualities reserved for certain temperaments.

Becoming a manager for the first time: the five most common mistakes

Most of the mistakes new managers make resemble one another. They don't come from a lack of commitment: they come from the fact that you generally learn management without explicit preparation, on a real human scope, with direct consequences for people.

• Continuing to do the work in the team's place rather than delegating
• Wanting to be liked by everyone rather than setting a clear framework
• Putting off difficult conversations
• Failing to clarify expectations from the start
• Believing that having been managed is enough to know how to manage

The first mistake is to keep doing the work in the team's place. You know the subject better than your team members: that's likely. Taking back their tasks is nonetheless counterproductive. It deprives them of autonomy, overloads you, and sends the signal that you don't trust them. Delegating effectively doesn't mean giving up on quality: it means clarifying expectations, leaving the method to the person, and checking progress at defined intervals.

The second mistake is to confuse popularity with authority. Some first-time managers fear losing their relationships by making firm decisions. They avoid touchy subjects, grant favors, let problematic behavior slide. In the short term, that preserves the mood. In the medium term, it weakens credibility: it becomes increasingly difficult to take back control without the correction seeming harsh or arbitrary.

Putting off difficult conversations is the third mistake, and certainly the most costly over time. A performance issue not addressed at day 15 becomes a deep-seated problem at day 90. Feedback shouldn't wait for the annual review: it should be frequent, factual, and close to the event that prompted it. The longer you wait, the harder the conversation becomes to have and the less useful it is for the person concerned.

Failing to clarify expectations from the start creates a confusion the team won't spontaneously verbalize. Who decides what? What are the priorities? How is success measured? These questions seem basic, and yet many new managers leave them unanswered, assuming that everyone reads the situation the same way.

The fifth mistake is to believe that having been managed is enough to know how to manage. You observed your own managers for years. You have intuitions about what works. That's a starting point, not training. There's a difference between recognizing good management and knowing how to practice it yourself, under pressure, with different personalities and concrete stakes.

Managing your former colleagues: the challenge no one prepared you for

The majority of first-time managers step into the role within the team where they already worked. It's the most common configuration, and also the most delicate. Overnight, the relationship with colleagues changes in nature: you're now responsible for their evaluation, their goals, their blockers, sometimes their conflicts with one another.

The first instinct is often to act as if nothing had changed, so as not to break the bonds you've built. That's a mistake. It's better to explicitly name the change of role, from the first days, with each member of the team in a one-on-one meeting. It's not a declaration of rupture: it's a way to set a clear framework, for you as much as for them, and to keep everyone from silently wondering what it implies.

The other risk is the opposite: distancing yourself abruptly to assert authority. Multiplying signs of hierarchy, cutting off informal exchanges, adopting a formal register with people who knew you in a different light. This overcorrection creates confusion and quickly erodes trust. Consistency over time is worth more than any strong signal at the start of the role.

Some managers in this situation also feel doubt about their own legitimacy: "Why me rather than them?", "Do they really accept me in this role?". If you recognize yourself in these questions, reading our article on impostor syndrome at work may round out this reflection.

Delegating, giving feedback, communicating: three skills that can't be improvised

These three skills come up in every analysis of first-time management. What they have in common is that they're counterintuitive: you think you've mastered them because you experienced them from the team member's side. Exercising them as a manager is another kind of learning.

Delegating effectively requires clarifying the expected results, not the methods. If you explain how to do it in detail, you're assigning a task. True delegation leaves room on the how while being firm on the what and the when. This distinction seems subtle: its effects on the team's autonomy and motivation, however, are very concrete. A team that knows you trust it on method works differently from a team that waits for your instructions at every step.

Feedback works better when it's frequent, brief, and factual. "You handled Tuesday's meeting well" is less useful than "The way you steered the discussion on deadlines back on track made it possible to reach a decision in twenty minutes instead of postponing it." Precision makes feedback reproducible: the person knows what to do again, not just that they did well.

Managerial communication isn't just about informing. It consists of adapting the message to the other person: their level of autonomy, their need for information, their preferred channel, their context at the moment. A manager who communicates the same way with everyone communicates effectively with no one. This adaptation rests largely on emotional intelligence at work, a skill that many first-time managers underestimate in the first months on the job.

Preparing your managerial transition: training before the first mistakes

There's a received idea that management is learned on the job. That's true. It's also learned on real people, with real consequences for their work, their motivation, and sometimes their desire to stay in the team. Learning by trial and error has a cost that turnover and absenteeism figures end up reflecting.

A management training beforehand or at the very start of taking on the role shortens this learning cycle. Not by providing recipes: by giving a conceptual framework for reading situations, a space to test postures without immediate consequences, and feedback from peers going through the same transitions. Contact with other first-time managers is often what participants cite as the most useful, ahead of the theoretical content itself.

There's also something difficult to admit for many new managers: they were promoted because they were good in their field, not because they had demonstrated managerial skills. Training makes it possible to name this gap without being ashamed of it, and to begin closing it before the first mistakes settle in as habits that are hard to undo.

The team management program at HEC Lausanne Executive Education is aimed precisely at professionals transitioning into supervisory roles. It combines conceptual input and concrete role-playing exercises, with a schedule designed to fit around a full-time professional activity.