Take the bull by the horns
Definition 1 of 1
Pro Tip 1/3Metaphorical Usage
The phrase is a metaphor, suggesting the control and daring it would take to literally grab a bull's horns. 
She took the bull by the horns and led the project despite her lack of experience.
Pro Tip 2/3Conveys Initiative
The phrase often implies that someone is taking initiative in a difficult situation without being asked. 
When the negotiations stalled, he took the bull by the horns and proposed a new deal.
Pro Tip 3/3Positive Connotation
Using the phrase usually has a positive connotation, praising someone's courage or decisiveness. 
The teacher took the bull by the horns and revamped the outdated curriculum.