Toss-up

Meaning:
When it is hard to choose between two choices.  This idiom refers to when you toss a coin up the air to decide which to choose based on how the coin lands.
Example Sentence:
There are two movies I really want to see but I can’t decide which one to go see first, it is a toss-up.

Last but not least

Meaning:
The last thing or person mentioned is no less important than what was mentioned earlier.
Example Sentence:
At the end of her award acceptance speech, Michelle said “last but not least, I would like to thank my parents for all of their support”.

Clear the air

Meaning:
To get rid of unpleasant air and replace it with fresh air. To discuss an unpleasant situation with the intention to make it better.
Example Sentence:
I can tell me wife is upset with me but I don’t know why, we really need to clear the air.

Soldier on

Meaning:
To continue to do an difficult task despite pain or setbacks.
Example Sentence:
I almost quit my terrible job yesterday but I decided to soldier on until I can find a better one.