six of one, half a dozen of the other

a dime a dozen

So common as to be practically or almost worthless.

all over hell's half acre

All over the place; everywhere.

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.

baker's dozen

Thirteen; a group of thirteen.

baker's half dozen

Seven, a group of seven.

banker's dozen

Eleven.