pull your socks up
pull (one's) socks up
To try to improve one's performance or behavior because it has not been good enough recently. We expect our writers to contribute about 15 articles per week, so you're going to have to pull your socks up if you want to stay a part of this team.
pull your socks upBRITISH
If someone tells you to pull your socks up, they want you to improve your behaviour or work. If he wants to continue in the job he'll have to pull his socks up. She was told by the boss to pull her socks up.