one thing led to another

another nail in someone's coffin

An event that increases the likelihood of or causes further failure.

another string to one's bow

Another skill, ability or resource to be used in case of failure.

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.

be a thing

To exist, or to be available, widespread, possible, or a common practice.

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.