These meridian stretches are for the stomach meridian. It runs down the front of the neck and body, across the front of each hip, down the front of each leg and across the top of each foot. It's shown by the yellow lines in the picture.
You can stretch the stomach meridian by
Because it passes above and below the lips you can also affect it by smiling. (Unlike myself in some of these pictures.)
Meridian stretches for the front of the neck are quite simple. You can bend your neck backwards. Prior to doing this, sit up straight and lift your chest and lengthen your neck.
Focus on feeling your cervical vertebrae as you bend your neck backwards. Keep your neck long and your chest open. Try to move your head away from your ribcage.
Slowly lift your head to come out of the stretch.
Another meridian stretch for the front of the body you may already have done when stretching the front of the shoulders. It is puppy dog stretch.
For puppy dog yoga pose, start on all fours.
Reach your hands ahead of you and slowly lower your ribcage towards the floor. Reach your chin forwards and continue to focus on bending your entire spine backwards. (Lift your back ribs.)
Breathe into your ribcage so that each exhale you relax deeper into the stretch.
Alternatively, start from a laying down position. Lift your hips and move your ribcage back. Reach your chin forwards and rest your chest on the floor.
As your chest and spine relaxes, move your ribcage further back. You can also reach your arms forwards.
Meridian stretches for the front of the hip include tilting the pelvis backwards and lunging while sinking the pelvis down.
One way of tilting the pelvis backwards to stretch the stomach meridian is to do a standing back bend (not shown.)
You can place your hands on your hips or in put them together in front of your heart.
Another way of doing a stomach meridian stretch for the front of the hip is to do a lunge.
Start with your left leg forward and your right leg back.
Note, in the picture my knee is completely straight. It doesn't have to be. You may find that just taking your knee off of the floor increases the stretch quite a bit.
If you want to practice control and sensitivity, focus on slowly activating your back leg and on lifting your knee just clear of the floor. Then slowly touch it down to the floor and slowly relax. You can add "lifting and lowering your arms" to this action. This again will require control. You'll have to lift your knee really slowly so that your leg and arms arrive at their end points at the same time.
You can do the following meridian stretches to stretch the front of the knee, ankle and possibly the hip. All of them are variations of hero pose (virasana).
You can do half hero pose (ardha virasana), where one knee is bent or you can do full hero pose where both knees are bent. If you lay down, then the pose is called reclining hero pose(supta virasana) or reclining half hero pose (supta ardha virasana.)
Note that if your knees are stiff and tight, you'll have to work into these poses slowly and gradually. If when you kneel your buttocks can not touch your heels (and assuming you haven't got extra long shin bones or extra short thigh bones) then try placing a block or severral blocks between your heels and sitting on them. Gradually reduce the hight of your seat, taking the time to get comfortable in each new position. At the same time, gradually widen your feet so that they are far enough apart that you could touch your bum to the floor between them.
In half hero pose you can fold one leg back and straighten the other leg. Start with your left leg folded back. Sit up tall. Try to sink your left sitting bone to the floor. (The sitting bones are the bones you feel at the base of your pelvis when you sit down on a hard chair or on the floor.) To aid in this, lift your arms and reach your ribs, arms and head up to the sky. You pelvis will press down as a result. Keep your left sitting bone pressing down as you lower your arms. If you are ready, lean back on to your elbows. Hold here if you need to. Focus on relaxing your left thigh.
If comfortable you can lay down and touch your shoulders to the floor. If you can't reach, place cushions or lots of books under your back and lay down on this improvised couch. To help your left thigh relax you can try shifting your chest and pelvis left or right, towards your foot or away from it slightly. Also play with the position of your left knee, moving it slightly inwards or outwards to see if you can find a more comfortable position for your left hip.
Do all of these adjustments slowly and smoothly. Feel your left, hip and lower back as you do them.
You can reach your arms back if you wish. If you do, focus on reaching your arms, head and ribcage back, away from your pelvis.
For an extra special bonus stretch, bend your right knee and place your right foot on the floor. Use your right leg to lift your pelvis. Try to keep yoru left knee on the floor as you do so.
Another option (not shown) is to drop your pelvis to the floor and use your arms to pull your right knee to the chest. You may need to press your elbows into the floor to help you balance.
If you are a bit more flexible you can do this with your right knee straight.
To come up use your elbows and hands.
I find that in the full version of hero pose it is easeir to keep my abdominals engaged. Why would I want them engaged? Because I find that this pose compresses my lower back alot. Engaging my abs and bending my spine forwards helps to remove that compression.
In full hero you fold both knees back at the same time. Widen your feet so that you can sit between them. If you need to, spend some time sitting and allow your pelvis to gradually sink down. (Use a block between your feet and sit on the block if you need to.)
To get used to leaning back, you can tilt your pelvis backwards and round your back. Bend your spine forwards. (Second picture below.) See how far back you can roll your pelvis while keeping your spine bent forwards and your abs engaged.
Place your elbows on the floor when you need to an either hold or gradually lower your head and then shoulders to the floor.
Once your shoulders are on the floor, you can lift your head and imagine lifting your ribcage to engage your abs. This should help to decompress your lower back. Once you get your lower back close enough to the floor, you can try reaching your arms back. Lengthen the back of your neck at the same time.
As with half hero pose, play with the distance between your knees to see if you can find a position that is "comfortable" for both your knees and hips. By comfortable, I mean no "sharp" pain in your joints.
To come out of this stretch you can use your abdominals and sit up, or prop yourself up with your elbows and hands.
To balance these stretches for the front of the body, stretch the back of the body.
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.