Toward repairing the world: it’s up to us to maintain it, continually correcting our course—not for the sake of personal gain (although through the making of things there’s an exchange that’s sustaining) but because of loving the world fiercely and wanting to make something that is a gift for its benefit, an offering, which operates by awakening delight in beings who encounter it and inhabit it.
Mastery is not finality but refinement. Acknowledgment and recognition for doing something well are helpful but too easily mistaken for an end-state or goal (useful but not sufficient).
Restraint provides a necessary resistance to being overwhelmed by the vastness of the task. Allowing the action to arise without becoming an actor may be tricky, but ultimately there's no other way to do something as a full offering. By getting out of your own way you can become receptive to something that helps move toward fuller awareness. Is this completion? So far no, only further development.
Mastery is only relevant if it develops with this attitude of moving forward, not getting stuck. Getting stuck is inevitable at certain points and getting unstuck is part of the process of developing mastery, but isn’t itself mastery. Mastery does imply a certain facility with disentangling.
The term mastery also implies a power relationship—think of slavery. Domination is essentially a non-ecological attitude. But considering the origin of this term, we can see some ambiguity: the word “dome” (which, as well as referring to a hemispherical roof, is also the French and German term for cathedral), comes from Latin domus and Greek dōma, meaning house, and shares the same root as dominion, domain, dominate and domestic (and also danger and despot). So somewhere along the way, we might find a positive (or at least neutral) connotation—something like “householding.” Of course, in the cultures that produced this idea, a householder was thought of as the authority—the master of his domain—and the most developed moral codes of the day required ethical treatment of one's slaves but did not question the existence of slavery. 
The phrase from Genesis that’s often been cited as a philosophical basis for exploiting the earth, “You shall have dominion over all the living beings” seems to be a mistaken translation. The Hebrew prefix a (b’) attached to a word means “with”—not “over.” So that statement more reasonably reads, “You shall rule in relation with all the living beings”—a much more ecological statement.
 And of course it’s important to be compensated and rewarded for one’s labor.
 Though it’s not unrepresented in other animal species, and popular interpretations of Darwin contend that competition for resources is the law of nature—but now we recognize that within most species, and even among different species, cooperation is the norm, and that predator-prey relations tend to operate in dynamic balance, unless disrupted by, for example, human-induced habitat destruction.
 The Latin word for God, Dominus (typically translated as “Lord”) means something like Master of the World.