Building a valuable network is all about establishing fruitful connections that can provide you with valuable career advice and problem-solving tips—and vice versa.

However, like all good relationships, they need due care and attention. So where to start?

Trim the tree
The main reason people struggle to generate fruitful connections is they simply have too many. They haven’t focused on those who are most important. Hindu Monk and business coach Dandapani explains that if we wish to attract and commit energy to new things, we need to free up capacity by ridding ourselves of “energy vampires,” or people who suck up all of our time and resources.

What you need now might not be what you need later
When figuring out which connections deserve your attention, take a long-term view. Some of my most fruitful connections are those who didn’t deliver a lot at first, but over time created a meaningful exchange that slowly grew.

See also: The One Thing You Need to Stop Doing at Networking Events

Give to get
Operate on the idea of a value exchange. One of the many side benefits of writing and blogging, for example, is you build up a library of content to send to your network. Create a group in your contacts and share books, podcasts, or blog posts you find interesting (be sure to bcc). Sending quality information to people who are helping you is a great way to nurture your network. (I often send these Fortune articles.)

Never eat alone
From traveling continuously over my career—and now a lot for the work I do at Xero—I’ve established a global network. There are always people I’d like to try to see, but I only have a limited amount of time. So when I am in a certain city, I need to be smart with the time I do have. The one rule I follow is to never eat alone. I always look for a connection to share a meal with. There’s something very honest about eating together, and over the years, I’ve found it leads to stronger relationships. It can also be a good way to figure out who you truly want to build a relationship with. Generally, if it’s not someone you would share a meal with, do you really want to have them as a trusted advisor?

Dedicate time to your own development
Taking the time to plant some roots for yourself is critical. After all, if you don’t look after yourself, you’ll have nothing to give when you’re trying to build relationships or create a value exchange. This part of networking isn’t often discussed, but it’s critical for establishing relationships. For me, this doesn’t necessarily need to be linked to work. My interest in Hinduism and meditation, for example, has enabled me to make remarkable business connections that I would never have made without planting my own new trees.

Say thank you
While it should go without saying, many of us forget to express gratitude—whether it be to ourselves or our network. They are the two most important words you can use when building a relationship. Not only is it good for the soul, but it’s also a great way to circle back, reconnect, and reinvigorate a relationship.