I've found that personally, fully welcoming feelings is the most effective way of releasing for me. What I mean by this is to not suppress feelings anymore, to let them totally take you over, come right to the surface, and enrage you. Once you're not suppressing anymore, they come up and out of their own accord. You feel them temporarily, quite intensely, but after that they're totally gone.

If I don't do this, I find that I get temporary relief from problems, or I feel as if below the surface the problem is still there in the background and I wake up the next morning feeling the same or only slightly different.

If you don't see how this works, I challenge you to totally welcome your feelings and frustrations. Not just admit them, but WELCOME them into your BODY and get really fucking mad about them and how you feel. It's only then are you fully tuned into them, and they can be released.