How to string words you like to form adjectives

If you read the newspapers, you will come across the use of adjectives formed by stringing words together by hyphens. The following is such an example:
A 20-year-old man was found sprawling in the middle of the road with blood oozing from the wounds from all over him.
'20-year-old' is an adjective formed by stringing '20', 'year' and 'old' together by hyphens.

You can be creative by coining adjectives such as the following:
1 He gave a 'will-you-give-me-a-break' look.
2 He showed me a 'sack-me-if-you-like' face when he was very late and I was about to tell him off.
3 The salesgirl finally displayed her 'take-it-or-leave-it' look to the fastidious customer who had asked her to take down ten pairs of shoes for her to them on her feet.

Happy coining adjectives.