The initial idioms of the letter N

not open one's mouth	not out of the woods
don't patronize me	not place
don't play (around) with me	not put a foot wrong
not put it past	take no stock in
not put something past someone	not put stock in (something)
not quite	reveal (one's) (true) colors
reveal (one's) (true) stripes	not right in the head
not right now, thanks	rule in
not safe for work	not say boo (to anyone)
not say boo to a goose	not see any objection
not see the forest for the trees	see the point in (doing) (something)
see the point (of something)	not see the wood for the trees
not set foot somewhere	set the heather alight
set the heather on fire	set the Thames alight
set the Thames on fire	set the world alight