As ButcherBox has evolved over the past couple of years, one area that I’ve had to work on personally is my development as a leader.

My role, however, changed quite a bit from the early days of the company when Mike and I were quietly building ButcherBox out of Soldier Design’s Harvard Square offices. Now, we have more than 25 employees and deliver our boxes across the country.

As ButcherBox has grown, I’ve also needed to develop. While some aspects of leading larger and more complex teams come naturally — especially since this is my second go-around as a startup co-founder — I’ve learned that there are situations that could arise that my past experiences haven’t prepared me for.

And so, to make sure that I am the best leader I can be for ButcherBox, I did the one thing that everyone should do when there is an experience-gap that needs to be filled: I emailed a couple of people in my network whom I think are really great leaders, and whom I respect, and I asked for their advice. I told them where I am at, where the company is at in terms of growth, and my new responsibilities. The reality was that I needed to grow personally at the same rate as the company.

So they sent me some great feedback, which was helpful. But more importantly, they sent a bunch of book recommendations on how to be a better leader. So I immediately went out and bought seven books on leadership. Many you’ve probably heard of, including classics like Andy Grove’s High Output Management, The Effective Executive, Primal Leadership, and The Charisma Myth. And I kept going from there.

I like to read books. And when I do, I like to take notes in the margins. I always have a pen in my hand. If you look at the books I’ve read, all the corners are folded over, so I can look back, and there are notes on almost every page. I think to get the most out of these types of books, you have to be an active reader.

Here are some of the books that I’ve found have been most helpful as ButcherBox —and me  — continue to grow:

Mindset – This book is focused on the reality that there are two mindsets: A fixed mindset versus a growth mindset. The fixed mindset is exemplified by people who might suck at math in second grade and tell themselves that they will just never be able to get better at it. Individuals with a growth mindset approach the same experience and tell themselves, “I just need to work harder, or learn math in a different way, or get a tutor.”

So I am trying to apply that growth mindset here at ButcherBox, fostering a culture of personal growth versus fixed, which has been interesting thus far.

The One Thing: This is a good example of how I have been able to apply something I’ve read to the culture here at the company.  I read The One Thing,  which both my co-founder Mike and another entrepreneur had recommended. The premise is that if you want to get extraordinary results, you need to spend an extraordinary amount of time doing whatever that one thing is that is going to move the needle. The book delves into the importance of focusing, how multitasking is bullshit, that your inbox is your enemy, the power of habit, and the importance of time blocking.

So I tried to figure out what the “one thing” was for me that really moves the needle at ButcherBox, and then I had to make sure that every day, I blocked out two to four hours to just do that.

My one thing changed. When I read the book five months ago, my one thing was “To get customers.” So, I’d look at what we were doing with our automation email series, and try to figure out how to improve things there, can that move the needle? Then, I looked into what we were doing on the affiliate, the sales side, referral, etc. I’d dive into these and help other team members improve.

But now, my one thing is to develop as a leader, and that can involve me sitting down to read for two hours or reading articles about management or talking to mentors.

We even had the whole marketing team read The One Thing recently, and everyone loved it.

So now we are doing a “one thing” challenge, which is trying to see how many days of the workweek everyone can focus on doing their one thing. It’s been great, but it has been difficult for a lot of people, including myself.

A Guide To The Good Life: This book, which digs into the wisdom of Stoic philosophy has taught me the importance of only focusing on what you can control.

Most of the things that stress us out in life are out of our control, however, we can control our response to these challenges. This book has been helpful in a fast-paced startup environment where new challenges arise daily.

Traction: How Any Startup Can Achieve Explosive Customer Growth: This is a great book for Internet businesses and shaped our marketing strategy here at ButcherBox.

Unbroken: This Laura Hillenbrand book about Louis Zamperini, a track star and the survivor of a World War II tragedy, is just straight-up inspiring.

Shoe Dog: Phil Knight paints a great picture of the startup roller coaster and how even companies like Nike can start from the humblest of beginnings.

Ego is the Enemy:  This is a great read that teaches you the importance and power of humility. This is key to us at ButcherBox where staying humble is one of our core values.

I hope you get as much out of these books as I have, and I hope you’ll share some of the books that have inspired or helped guide you in business or life in the comments section below.