ride herd on

From the cowboy task of driving cattle while riding along with them.

• "As the new editor, his job is to ride herd on the staff and check on the tone of the articles."
• "But Rabbit feels as though he owns it all, showing up at the showroom day after day, riding herd on the paperwork and the payroll […]"
• "2013, Lori Wilde, Love at First Sight She'd gotten swept up in running the B&B and riding herd on her sister, Zoey, but she'd kept the faith."

• corral
• herd cats
• hold the reins