The initial idioms of the letter O

one-finger salute	one-horse race
rue the day (that something happened)	one-man show
one-to-one	show to advantage
be all in	(one's) ass off
(one's) autumn years	(one's) bag of tricks
One's bark is worse than bite	(one's) bark is worse than (one's) bite
one's bearings	one's best bib and tucker
one's best shot	one's better half
one's claws are showing	do one's best
one's days are numbered	one's deepest sympathy
one's ears are red	one's ears are ringing
one's egg money	one's eyes are bigger than stomach
one's fair share	one's fill of
one's for the asking	one's frame of mind
one's future looks bright	slip a cog