By body part
Eight practices that work on your hips. Every one runs right here in the browser, guided and free.

Opens up the hips, standing first, then the floor.

Opens the hips without ever taking you to the floor.

Deep, slow hip work, all of it on the floor.

Opens the front of the hips, which a chair keeps closed.

Slow stretches, all lying down, for the end of the day.

Gentle work for the lower back, moving the spine both ways.

Made for straight out of bed. Light and easy.

A little of everything, top to bottom.
Hips stiffen from sitting more noticeably than anywhere else, because a chair holds them at roughly ninety degrees for hours at a time and the tissue at the front settles into that length.
These practices work the hip in the directions a chair never asks for. Opening the front, rotating in and out, and taking the inner thigh wider.
Two honest notes. Hip flexor stretching reliably increases how far the joint moves, and that is a real thing to want. It does not change the tilt of your pelvis, and it does not switch the glutes on. Both claims are common and the trials do not support them. The reason to do this work is the range itself, and the fact that it feels good.
Expect the change within about four weeks of regular practice.
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