In the winter of 2003, I started my first business: a wholesale fashion agency. I was 27 and had no idea what I was doing. If I bumped into my younger self today, here are some thoughts I would share with him.

Know when to blow the whistle 

One glorious summer night, you’ll be rushing to the park to unwind from a very stressful week. As you get ready to toss the Frisbee to your mate, a park ranger will sound his whistle. Time to clear out: park closed. That disturbingly high-pitched sound notifying all visitors that it’s time to leave is also notifying you that it’s time to make a change.

The first change? Know when to part from your partner. Yes—a business divorce, if you will. Your partner turned out to be the source of most of the misery you felt, as well as the unhealthy stress you experienced. He wanted to make money, and quickly. You, on the other hand, wanted to develop a long-term sustainable business with steady growth, doing so through meaningful and lasting relationships.

All the risks of an enterprise going sour cannot be eliminated. But it shouldn’t be a surprise that many successful ventures are managed by long-term friends or family members who often share similar views of the world. Until they don’t.

Complacency kills

The popular Pareto principle states that 80 percent of your business will come from 20 percent of your customers. Listen to this closely. At one point, you will be deriving 80 percent of your sales from just two customers (albeit very large companies), and this is not sustainable over the long haul. When you have a diversified customer base and things are going well, it’s actually time to work even harder. Never become complacent. Always keep searching for the next customer, and the next opportunity.

A bigger team has more power

You have a knack for identifying and attracting talent. However, you aren’t smart enough to figure out ways to retain that talent. Develop a process and feedback loop that allows employees and freelancers to stick around. Better yet, find those stars that can help you create an environment where folks are happy and fulfilled. Aim to deliver on four principles: autonomy, mastery, purpose, and partnership. The first three are from Daniel Pink’s wonderful book Drive (which you should read at once), and the last comes from the progressive consultancy models of today, which are taking on more transparent and collectively minded organizing ideologies.

It’s okay to say no

This one’s pretty simple, but it’s something that will take you a very long time to learn. Saying no means saying yes to other things. The sooner you learn to say no to things that are not right for you and your business, the richer your work life will be. How will you know when to say no? Just listen to your gut.

Play leapfrog

It’s not just the leap to starting a business that takes chutzpah. It’s the smaller steps that aggregate like a ripple effect. What to start doing, what to stop doing, who to partner with, which territory to go to next—these are all mini leaps you take each day. Take them on full force.

Get the basics down

Don’t forget to “ask for the sale.” Be trustful, but verify and be sure to get paid. Lastly, always follow the Golden Rule.

An edited version of this post first appeared in The Huffington Post here