under one's own steam
Independently, without help, as in For two years I published the quarterly newsletter under my own steam. This expression uses steam in the sense of “driving power,” as in a steam engine. [Early 1900s]
Words nearby under one's own steam
under one's belt,
under one's breath,
under one's feet,
under one's hat,
under one's nose,
under one's own steam,
under one's skin,
under pain of,
under par,
under secretary,
under someone's spell