
I came across this really great article the other day on stretching. A lot of times people stretch after a workout and don't stretch the muscles used in their workout or don't even know what muscles they're stretching in their stretches. Stretching is so key to improve your range of motion, increase flexibility, improves posture, and of course promotes muscle recovery.
The article I read is by Sharen Ross of LifeHack.org. I'm sharing parts of the article below, but be sure to check out the full article here which details more about the stretches individually.
1. Camel Pose: Rectus Abdominus and External Obliques.
2. Wide Forward Fold: Adductors

3. Frog Pose: Adductors
4. Wide Side Lunge Pose: Adductors

5. Butterfly Stretch: Adductors
6. Forearm Extensor Stretch: Forearm Extensor

7. Lateral Side Flexion of the Neck: Sternocleidomastoid "SCM"
8. Neck Rotation Stretch: Sternocleidomastoid "SCM"

9. Neck Extension Stretch: Sternocleidomastoid "SCM"
10. Lateral Side Flexion of the Neck with Hand Assistance: Sternocleidomastoid "SCM"

11. Half Kneeling Quad/Hip Flexor Stretch: Psoas and Quadraceps
12. Forearm Extensor Stretch: Forearm Extensor

13. Lateral Shoulder Stretch: Side Deltoid
14. Standing Assisted Neck Flexion Stretch: Trapezius Muscle

15. Lat Stretch with Spinal Traction Latissimus Dorsi
16. Lat Stretch at the Wall: Latissimus Dorsi

17. Child's Pose: Latissimus Dorsi
18. Standing Calf Stretch: Soleus and Gastrocnemius

19. Front Split: Psoas and Hamstring
20. Seated Forward Fold/Seated Toe Touch: Hamstrings and Calfs

21. Single Leg Forward Bend: Hamstrings
22. Deep Squat: Glutes

23. Seated Half King Pigeon Pose: Glutes
24. Standing Calf Stretch at the Wall: Soleus and Gastrocnemius

25. Lateral Flexion at the Wall: External Obliques
26. Supine Twist: Glutes and External Obliques

27. Lateral Flexion with a Dowel: External Obliques and Latissimus Dorsi
28. Triangle Pose: External Obliques

29. Chest Stretch at the Wall: Pectorals
30. Assisted Chest Stretch: Chest and Latissimus Dorsi

31. Seated Half Pigeon Variation: Anterior Tibialis
32. Supine Shoulder External Rotation Stretch: Subscapularis

33. Down Dog Variation at the Wall: Pectorals and Latissimus Dorsi
34. Assisted Chest Stretch Variation: Pectorals
Source: http://www.lifehack.org/
The illustrations were created by Vicky Timón, a yoga expert and author of “Encyclopedia of Pilates Exercises,” and James Kilgallon, CSCS, creator of Mazlo’s Body Maintenance Program.