Leadership training is a $366 billion global industry, with writers and podcasters like Brené Brown, Adam Grant and Simon Sinek bringing fresh energy to the space in recent years. Leadership literature can be a brilliant tool: inspiring change, motivating success and encouraging leaders to strive for better. But with so much information out there, the leadership advice market can be an overwhelming, noisy space that can tend towards moralising.

As an entrepreneur in the business of optimising human performance, I’ve learnt that sometimes the most oft-cited thinking around leadership is still the best. Common threads run throughout new interviews, books, blogs and research papers, which are in fact time-worn tenets of leadership repackaged.

Instead of reinventing the wheel, reclaiming classic principles of great leadership is an effective way for time-strapped leaders to engage in best practice and inspire teams.

Here are five leadership clichés that are worth rehabilitating for the new world of work. Far from outdated and irrelevant, these old-school principles are universal observations on selling, influencing and inspiring, which continue to underpin global leadership strategies today.

1. Lead by example
One of the most well-known leadership books of the decade is Brené Brown’s Dare To Lead. In it, she talks about courage and vulnerability as the cornerstones of great leadership: in other words stepping up to the plate, being brave and not shying away from the tough stuff. The ‘tough stuff’ might be a difficult work problem, an issue with a colleague or a personal struggle with burnout. Whatever it is, the modern definition of leading by example should centre around showing your team your humanity and modelling positive ways to problem-solve. Gone are the days when ‘leading by example’ meant bluster, bravado and being the loudest person in the room.

2. The customer is always right
I’m not just talking about the customer in the grocery store who says the special offer hasn’t been recognised at checkout. I’m talking about the customers, clients, investors and stakeholders who business leaders must work with and impress every day. In the modern workplace, when a frustrating situation with a client arises that doesn’t align with your thinking, reminding yourself that ‘the customer is always right’ can help you see things from their perspective and deliver a diplomatic response.

Knowing that ‘the customer is always right’ need not be about rolling over and saying ‘yes’ to every request, but about learning to negotiate and present your view to unhappy customers in a sympathetic yet assertive way.

3. There are no stupid questions
It might sound patronising, but the ‘no stupid questions’ mantra is incredibly valuable when it comes to building a supportive culture that values learning and curiosity. A culture where there are ‘no stupid questions’ creates safe spaces for everyone – no matter how junior or senior – to ask burning questions without feeling shame or inadequacy. An environment that values this kind of open dialogue also breeds creativity, allowing every idea or question to be brought to the table freely and without judgement.

4. Think outside the box
Thinking ‘outside the box’ can be easier said than done. Often, when we’re suddenly called upon to deliver a big, creative idea, our minds draw a blank. Dismissing an idea that isn’t fresh enough with a command to ‘think outside the box’ isn’t generally useful. But the notion that thinking beyond the usual parameters of what’s realistic when generating ideas definitely is. Whether you’re trying to come up with a creative campaign idea or brainstorming a new product solution, starting with ideas that are outside of the realm of feasibility can breed creativity and spark original thought in others. It’s far easier to scale wacky ideas back, than to spice up ideas that lack that spark. Stepping outside the notorious box is a brilliant launchpad for creative thinking and innovation.

5. My door is always open
Like any tenet of great leadership, this one is empty if not genuinely intentioned and acted upon. Saying that your door is open doesn’t actually open it. But creating space for employees to come to you – and being attentive, approachable and present when they do – can make a world of difference to their satisfaction at work. It’s empowering for employees to know that they can come to leaders with questions, concerns or ideas. It helps them to feel as though their wellbeing and contribution is not only noticed but valued at the top.

Luckily, leaving your door open is easier than ever in the hybrid workplace. Employees no longer need to brave a leader or manager’s office if they want a quick chat or to sound something out. Instead, they can arrange an informal meeting over Zoom or even a phone call. The barriers to access are that much lower, meaning leaders are in a strong position to open a dialogue with employees and leave the metaphorical door wide open for when they need it. Blocking out time in your calendar each week when everyone knows you are available for informal one-to-ones can help you manage your time effectively whilst also making time for your team.