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

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

1. Mountain Pose (Tadasana): This is a basic standing pose that helps improve posture, balance, and core strength. Stand tall with your feet hip-width apart, arms by your sides, and palms facing forward. Focus on grounding your feet into the floor, lifting your chest, and elongating your spine.

2. Downward-Facing Dog (Adho Mukha Svanasana): This pose stretches the hamstrings, calves, and spine, while also improving circulation and calming the mind. Start on your hands and knees, with your wrists under your shoulders and your knees under your hips. Lift your hips up and back, straightening your arms and legs to form an inverted V-shape.

3. Child's Pose (Balasana): This is a gentle resting pose that helps release tension in the back, shoulders, and neck. Start on your hands and knees, then lower your hips back towards your heels as you stretch your arms forward and rest your forehead on the floor.

4. Warrior II (Virabhadrasana II): This pose strengthens the legs, hips, and core, while also improving balance and focus. Start in a lunge position, with your left foot forward and your right foot back. Turn your right foot out to a 90-degree angle, and extend your arms out to the sides, parallel to the floor. Bend your left knee to a 90-degree angle, making sure your knee is directly above your ankle.

5. Triangle Pose (Trikonasana): This pose stretches the hamstrings, hips, and spine, while also improving balance and digestion. From Warrior II, straighten your left leg and reach your left hand down towards your left ankle, while extending your right arm up towards the ceiling. Keep your hips squared towards the front of the mat, and gaze up towards your right hand.

6. Seated Forward Bend (Paschimottanasana): This pose stretches the hamstrings, spine, and shoulders, while also calming the mind and relieving stress. Sit on the floor with your legs straight out in front of you, and reach your arms up towards the ceiling. Then, hinge forward from your hips and reach your hands towards your feet or ankles, keeping your spine long.