Describe six effective yoga poses or stretches that are safe and excellent for people of all ages.

Here are six yoga poses or stretches that are safe and effective for people of all ages:

1. Mountain Pose (Tadasana): This pose focuses on standing tall with proper alignment, which helps to improve posture and balance. Stand with your feet hip-distance apart, arms at your sides, and shoulders relaxed. Ground down through your feet and engage your leg muscles. Lift the crown of your head up towards the ceiling while keeping your chin parallel to the ground. Take a few deep breaths in this pose to center yourself.

2. Downward-Facing Dog (Adho Mukha Svanasana): This pose stretches the hamstrings, calves, and spine while also strengthening the arms and shoulders. Start on your hands and knees with your hands slightly ahead of your shoulders and your knees hip-distance apart. Lift your hips up and back, straightening your arms and legs to come into an inverted V shape. Keep your head and neck relaxed, and press your palms and feet into the ground to deepen the stretch.

3. Child's Pose (Balasana): This pose is a gentle stretch for the back, hips, and thighs, and can also help to calm the mind. Start on your hands and knees, then lower your hips back towards your heels while stretching your arms forward. Rest your forehead on the ground and take deep breaths.

4. Warrior II (Virabhadrasana II): This pose strengthens the legs and improves balance while also stretching the hips and chest. Start in Mountain Pose, then step your left foot back and turn it out to a 90-degree angle. Bend your right knee and extend your arms out to the sides, keeping them parallel to the ground. Gaze over your right hand and hold for several breaths before switching sides.

5. Tree Pose (Vrksasana): This pose improves balance and strengthens the legs while also stretching the hips and spine. Stand with your feet hip-distance apart, then shift your weight onto your left foot. Lift your right foot and place the sole against your left inner thigh, pressing the foot into the thigh for stability. Bring your hands together at your heart center and hold for several breaths before switching sides.

6. Cat-Cow Stretch: This stretch improves flexibility in the spine and shoulders while also promoting healthy digestion. Start on your hands and knees with your wrists directly under your shoulders and your knees under your hips. Inhale and arch your back, lifting your head and tailbone towards the ceiling (Cow Pose), then exhale and round your spine, tucking your chin to your chest and pulling your belly button towards your spine (Cat Pose). Repeat several times, moving with your breath.