A breath of fresh air
Something new and refreshing.

When it rains, it pours
Problems or misfortunes tend to occur all at once.

To hit the hay
To go to bed or sleep.

To go with the flow
To accept things as they are and not try to change them.

A drop in the ocean
A small or insignificant amount compared to a larger whole.

To be in hot water
To be in trouble.

To have a green thumb
To be good at gardening or growing plants.

To take the bull by the horns
To confront a difficult situation directly.

To weather the storm
To endure a difficult situation.

To be a lone wolf
To prefer to act alone rather than as part of a group.

To hit the ground running
To start something and proceed quickly and effectively.

To go down in flames
To fail spectacularly.

To be on cloud nine
To be extremely happy.

To dance with the waves
To go along with the situation and enjoy it.

To make hay while the sun shines
To take advantage of favorable circumstances while they last.

To have one's head in the clouds
To be unrealistic or daydreaming.

To leave no stone unturned
To do everything possible to achieve a goal.

To be like a fish out of water
To feel uncomfortable in an unfamiliar situation.

To grow like a weed
To grow quickly and uncontrollably.

To be in the same boat
To be in the same difficult situation as others.