HIT AND MISS(ADJ.)
If something is hit-and-miss, you cannot depend on it to be of good quality, on time, accurate, etc.:
THINK LONG AND HARD
to take the time needed to understand something before making a decision about it:
BITS AND PIECES/BOBS
small things or jobs of different types
every now and again/then
sometimes but not often:
ON AND OFF
SOMETIMES
VERB+UP AND DOWN
in one direction and then in the opposite direction, esp. repeatedly
RULES AND REGULATIONS
directives made in addition to the laws in a particular country
LAW AND ORDER
a situation in which the laws of a country are being obeyed, especially when the police or army are used to make certain of this:
HERE AND THERE
In various places.
FIRST AND FOREMOST
You use first and foremost to emphasize the most important quality of something or someone.