The following basic yoga sequence is for general hip and spine flexibility.
It covers most of the mobility requirements for the hips and spine and also includes "reactivation exercises" at the end of the routine to reactivate muscles that have just been stretched.
The sequence is divided into three main parts. The poses in each part can be practiced as a mini-sequence if short on time, or if you want to focus on certain elements.
Move slowly and gradually into each position.
Feel your body and adjustment for comfort.
Work at making your body feel "expansive".
Creating space or length is stretching at its most basic.
Note that at a certain point a lot of what holds you back from improving flexibility while stretching will be your mind and your preconceived notion of how flexible you are. Practice imagining that you are already flexible.
In each case anchor your ribcage so that your neck muscles have a firm foundation from which to work on your neck.
Lead each movement with your ribcage.
For the forward bend pull down on the front ribs.
For the back bend pull down on the back ribs.
For the twist, turn the ribcage in the direction your are turning your head.
For a deeper stretch focus on feeling the individual vertebrae of the neck as you twist, side bend, back bend and then front bend the neck.
This sequence of two poses stretches the quadriceps and also sidebends and then twists the spine. The basic position is to kneel with one leg while the other leg is folded inwards with the foot against the inner thigh of the kneeling leg.
If you can't sit on your heels while kneeling regularly, then sit on a yoga block for this pose.
If you work at sinking the hip to the inside of the kneeling pose, then this pose stretches the quadriceps of the kneeling leg.
First sit upright and work at sinking the hip of the kneeling leg to stretch that quadriceps. The ideal is to get the butt to the floor inside the foot. Adding a side bend (towards the kneeling foot) adds weight to the quadriceps stretch.
Bend to the side slowly to gradually add weight to the quad stretch and then reach one arm at a time in the direction of stretch.
Try to lengthen both arms and both sides of the waist.
If your knee hurts then try placing the bottom most hand on the floor to take some of the pressure off of the knee. If possible, press down with the other leg.
Moving into the twist press down with the non-kneeling knee to give you some leverage and use the weight of your body to help press the hip of the kneeling leg downwards.
Draw the upwards on the ribs so that your waist feels long and your ribcage feels open. Work at creating space between the ribs giving you room to deepen the twist. You can also twist away from the non-kneeling leg.
For the next in this sequence of yoga poses, sit with one foot flat on the floor and the knee bent and pointing upwards. The other leg is folded inwards with the foot behind the heel of the squatting leg.
Bend forwards allowing your hips to lift. Reach forwards with the squatting-leg-side arm and use your other hand to help balance while your hips are lifted. Lengthen the reaching arm and the side of the body as well as the neck.
Hold this position for a few breaths and work at getting the back of your ribcage below the top of the knee. This improves flexibility at the back of the hip.
When you are ready (and this may take some practice) reach the arm outwards across the front of your squatting-leg shin. You can use the other hand to pull the shin inwards.
Hold this position, making the arm feel long. Then try to rotate your arm inwards enough that your elbow points forwards. To make internal rotation of the shoulder easier you may find it helps to reach the shoulderblade sideways away from the spine.
Bend your elbow and reach the hand behind the lower back so that it can grab the wrist of the other hand. When taking the other hand off of the floor use your feet and legs to support your hips.
Keep your hips lifted. Press your arm back against the shin. Use it to stretch the shoulder of the other arm. Press your arm back against your shin to help maintain your forward bend. To deepen the position (and also to help strengthen your hip extensors) you can use your hip muscles to press your shin forwards against your arm.
Try the above actions with your butt on the floor also.
This stretch can be used to stretch and strengthen the outer hip as well as twisting this spine.
(Modified Ardha Matsyendrasana)
With one leg folded inwards, step the other foot over the first leg so that the foot is to the outside of the knee of the bottom leg.
Pull inwards on the top leg with the opposite arm. At the same time resist the arm by pushing the leg outwards. Match the strength of the arm to the leg so that the leg remains vertical (knee pointing upwards). With the other hand on the floor behind you you can use both arms to twist your ribcage.
To deepen the twist (and strengthen your waist) try using your waist muscles to help turn your ribcage relative to your pelvis.
(Compass Pose Prep)
Make the leg feel long. Push the foot outwards against your hands. Lift your chest.
If you have tight hamstrings use a strap to hold the foot. Start with the strap long so that you have room to straighten your leg. Then gradually shorten the strap to the point that you can grab on to your foot.
Once you have your foot keep your elbows straight and chest lifted. Then to increase the stretch keep your chest lifted and bend your elbows.
The next pose in the sequence (Upright Pigeon) stretches the hip flexors.
Sit with one leg forwards with the knee bent and the other leg back. Rest the hip of the forward leg on the floor and position the shin of the front leg parallel to the front of your mat. Position the knee so that it is outside the hip when viewed from the front.
Point the back knee downwards as much as possible. Straighten the back knee (not shown) and reach back through the back leg. Bend your spine backwards. Use the front-leg-side arm to help push the ribcage towards the back-leg side. Push down with your front knee to help push your ribcage to the side. As you do so notice the back-leg-hip sinking closer to the floor.
The above sequence of stretches can be done first on one side and then on the other. Or do each of the poses on both sides before moving on to the next pose. This could be though of as a mini-sequence. If you are short on time then you can use this sequence of poses by itself.
As a yoga teacher, I'm constantly exploring new exercises, new ways of doing yoga poses.
There is no single "right way" of doing a yoga pose. Instead, there are options. And the better you are at "feeling" your body, the better you can get at choosing the right option for your body as it is now.
For any technique, the point of practice is to learn feel it and to control it, so that it can be used without thinking about how to use it.
And that is more or less the approach taken in all of my ebooks and videos. They help you to feel your body and control it so that you can work towards using it effectively in anything that you do.