If you have been stretching and you're not feeling any looser, chances are you don't have a stereotypical tight muscle that "just needs to be stretched". Muscles get tight for many reasons and if you're finding yourself still tight after stretching, chances are you need to strengthen, or stabilize, the region around your tightness. Your muscle is tight because it is trying to provide strength/stability to an otherwise weak area.
Let's take the calf for an example, a commonly tight area, and an area most people know how to stretch.
You finish this stretch and you still feel tight. Two things I have found successful are 1) working on stabilizing the ankle so the calf can relax (not be tight) and do it's own job (provide strength in pushing off when you walk or run) and 2) ensuring the lumbopelvic area is properly aligned and stable to allow optimal nerve flow through the sciatic nerve (that innervates the calf) and thus allows the calf, once again, to relax and do its own job.
Practicing single leg balance can be an option to stabilize an ankle.
Rolling is a dynamic way to stretch and strengthen at the same time. Adding straightening of your leg, with toes up, on your tight calf side can be the missing link to allowing your tight calf to relax.
Shallyn's Physical Therapy and Wellness Services strives to take an in-depth look at each individual's presentation and treat it most effectively and efficiently. Shallyn's can help decipher which "stretching" technique will be most effective for you and be your hands (to optimize movement) and eyes (to ensure proper exercise technique) to get you started on your independent road to greater muscle relaxation.
Tidbits from your physical therapist.