Pretty much all yoga poses are for flexibility, but here are some that concentrate on particularly tight parts of the body.
Hamstrings: Poses that stretch the hamstrings include standing and seated forward bends. In these poses, you get a better stretch if you keep the spine long rather than allowing it to round as you come forward.
Hips: Hip openers can be tough going for beginners who have been sedentary in the past. If you have trouble, take them slowly and make use of props such as blankets and blocks to make the poses more comfortable.
Shoulders: Many advanced yoga postures, such as full wheel, full pigeon, and forearm stand require not only strength and balance but open shoulders. There are also a number of stretches beginning and intermediate students can do to prepare.