HOW: Get set-up standing with one foot on a slider, the side you want to target will be the one on the slider. While staying tall and stable throughout the rest of your body, perform isolated hip extension by sliding your foot backwards on the slider. Simultaneously lip your arms up overhead. Repeat
FEEL: You should feel a stretch in front of your hip as well as your butt muscles working on the side you're sliding. Your other hip and core muscles will be working as well to maintain body position.
COMPENSATION: Do not arch your back or lose body position, perform isolated hip extension.