Be giving. Do not steal.
In the time since I first took the vow to not steal I've really come to reflect more on the giving side of this precept. Perhaps it is because I've really looked at the Seventh Grave Precept much more closely, where we're encouraged further more to give generously. With reflection I've considered more the ways in which I want to not give, to not share my time or energy. "Robbing" other people of those intangible things.
I've also thought about the times when I try to over-extend myself, wanting so much to please another person that I'm willing to deplete, "steal" the energy I need to stay healthy. For some of us it is far to easy to be giving to the point of self-harm (and there we go breaking the First Grave Precept). People like it when you give, but we have to be willing to extend that generosity to ourselves as well.
On the other side is recognizing that other people need to set boundaries like this. Taking advantage of someone who gives generously and then being frustrated when they say they cannot feels to me as though it would fall into being weighed by this precept. Working with it has made me more aware of how people share with me (in ways emotional, material, and otherwise) and how I am given the opportunity to respond in kind.
Because I've spent a lot of time reflecting on my veganism I've also come to see how this precept applies to my interaction with animals. Just as I should not take advantage of a person's good-nature and willingness to help out, I don't feel it is right to take advantage of animals, to be part of the industry that "steals" their calves, etc. It is more giving to to animals to nurture myself on a plant-based diet