Here are some idioms which use items of clothing:
Used to describe a boring person with an uninteresting hobby who always talks about it - they are too interested in unimportant details:
'He's such an anorak. He's always talking about the history of steam trains.'
To admire or respect someone:
'She got 100% on the test. I take my hat off to her.'
Something to be proud of; an honour:
'Winning the essay writing competition is just another feather in her cap. She has lots of talents.'
A comment or action which is considered abusive, overly hurtful or plain unfair:
'I thought it was a bit below the belt when he called her old.'
Not modern or exciting; old fashioned:
'He may be old hat among the trendy younger generation, but his shows draw more viewers than any other comedian.'