one brick short of a full load

a day late and a dollar short

Too late and too feeble to achieve the desired effect.

a short drop and a sudden stop

A fall to one's death by hanging.

as best one can

In the best possible way, given one's circumstances and abilities.

as far as one knows

To the best of one's knowledge, as far as someone knows or possible information to be gathered about the topic, subject, aspect, or situation.

back to square one

Located back at the start, as after a dead end or failure.

bang one's head against a brick wall

To waste effort on a futile project.

beat as one

To share the same feelings.

become one flesh

To join together in marriage; to develop a unifying bond as a result of marrying.