Let’s get started:

1. Spice things up

You’ve probably guessed by now that to spice things up means to make them more interesting or exciting.
Instead of just buying Sam a birthday gift, let’s spice things up by taking him out for dinner.

2. A piece of cake

A piece of cake refers to a task or job that’s easy to complete or accomplish.
I expected the English test to be difficult but it was a piece of cake.

3. Cool as a cucumber

Cucumbers have a refreshing taste and leave you with a cool, calm feeling. So if you’re cool as a cucumber, you’re someone who’s very calm and relaxed.
My friend is nervous about taking his driving test but I’m cool as a cucumber.

4. Couch potato

A couch potato refers to someone who spends a lot of time sitting on the couch watching TV.
After my uncle retired from his job, he became a couch potato.

5. Bring home the bacon

To bring home the bacon means to make an income or earn a living to support your family.
Ever since her father was injured, she’s been working two jobs to bring home the bacon.

6. In hot water

When someone is in hot water, they’re in a bad situation or serious trouble.
My brother is in hot water for failing all his college classes.