Iron Out and Feather In One's Cap

Today's phrasal verb is iron out, which means
To remove small problems or irregularities. To settle through discussion or compromise. It is similar to the phrasal verb, work out.

The management team ironed out the tax problems before they gave the project the OK.
The lawyers ironed out the final details of the contract during a long meeting.
The baseball pitcher ironed out the problem with his curve ball.
I'm ironing out the wrinkles of what is slowing my computer down. 

This expression, iron out, is often followed by the nouns "wrinkles" or "kinks". 

Today's idiom is a feather in one's cap, which means
An accomplishment; particularly one that is boasted of or bragged. 
An act or deed to one's credit; a distinctive achievement.
A symbol of honor and achievement. 

He thinks it is quite a feather in his cap that he figured it out for himself. 
It's a feather in your cap that you received the highest grade on the test.

The placing of a feather in a hat has been a symbol of achievement that has arisen in several cultures, apparently independently.The Native American tradition of adding a feather to the head-dress of any warrior who performed a brave act is well-known.