Air/wash one`s dirty linen in public

To air/wash your dirty linen in public is to discuss your private problems and quarrels in front of others.

• If she was a sensible woman, she wouldn’t wash her dirty linen in public.
• They broke up because he was angry with her for washing her dirty linen in public.

All dressed up

When you are all dressed up, you are dressed in your best clothes.

• The little girl is all dressed up for her birthday party.

As comfortable as an old shoe

If something is as comfortable as an old shoe, it is very comfortable.

• I am as comfortable as an old shoe when I am in my uncle’s house.

As common as an old shoe

If somebody is as common as an old shoe, they are low class.

• Her crude manners proved that she was as common as an old shoe.

As tough as an old boot

If something is as tough as an old boot, it is very tough.

• The old lady is as tough as an old boot. She hardly ever shows her feelings.

At the drop of a hat

If something happens at the drop of a hat, it happens immediately.

• Rita is quite sensitive. She would cry at the drop of a hat.

Beat the pants off (someone)

To beat the pants off somebody is to beat them badly.

• When I played tennis with my sister yesterday, she beat the pants off.

Best bib and tucker

Your best bib and tucker is your best clothing.

• He wore his best bib and tucker to the interview.