The relationships you have with other human beings are important. While such a statement may seem self-evident, most people don't think about the fact that who you know (and how they feel about you) is what will open doors, result in partnerships and alliances, give you access to the advice you need to hear, and bring business opportunities your way.

But establishing and maintaining relationships takes work. And according to Jason Harris, author of The Soulful Art of Persuasion, too often they disappear altogether out of sheer neglect. In his book, which I highly recommend, he offers five strategies to nurture your relationships.

Give yourself a reminder

If you truly don't want to lose contact with someone, set a recurring notification to remind yourself to reach out to them at least once a quarter.

Choose four people every week to connect with

Even a text message letting them know you were thinking about them can suffice. Harris makes it a practice to have regular one-on-ones with every person employed by his company. It's time consuming, he admits, but it provides an opportunity for him to hear what a person needs to succeed, as well as their ideas for improving the company. It also allows him to build authentic relationships with everyone he works with which only helps the organization function better.

Make recommendations personal

Instead of posting on social media about something which impressed you, sift through your contacts and pick a few people who would appreciate the recommendation. This is a great way to start a conversation.

Find ways to introduce people

If you know someone who would benefit from knowing someone else in your network, find a way to put the two people together. They can take it from there. "Your goal is to value relationships for their own sake," he writes, "and that includes other people's relationships."

Think of "no" as "no for now"

The big mistake Harris says people make is valuing transactions over relationships. It doesn't matter if someone says no to your idea or request. If you're truly interested in having a long-term relationship with this person, you'll keep in touch and have more conversations at a later date. The relationship very well may result in even better opportunities some day in the future.