Mutual respect. The key word being mutual.
In fairness, I don't think it's entirely one sided. Sometimes it seems as though there are views among some non-binary individuals that, as a group, people who view their gender as binary are relics of a bygone age, archaic in their thinking and limited in their perception, and that non-binary identification is heralded as a new dawning of humanity. It doesn't take a great deal of looking to see how that can rub people the wrong way just as much as the skeptical views of some binary identified people about the existence of any identification outside the binary model.
The need for some people to live as part of the binary is often as little understood by non-binary people as the reverse is for binary identified people.
Acceptance of others comes partly with acceptance of oneself, but also with the understanding that what makes some people one thing, and some another, is neither better, nor worse - neither less nor more valid - just different. And, if not seeking to understand, then at the very least respecting and embracing these differences free from prejudice and with an open mind - knowing that what makes your neighbour who they are contributes no more and no less to your own internal makeup than them eating a heavy meal would give you heartburn.
This can only be achieved when everyone shares one commonality - the understanding that all people have equal right to an identity, be that binary or non-binary.
