I mentioned this experience in herbavore's Mindfulness Thread some time back - it's still in TDS. My old therapist taught me about Mindfulness Meditation as part of ACT (Acceptance and Commitment Therapy). It was a fantastic concept to learn about, and subsequently, to practice & incorporate into my life!
Below, I'll quote what I wrote in the original Mindfulness Thread

---------
I was introduced to Mindfulness whilst seeing a Cognitive-Behavioral Therapist about three years ago. She began working with me out of a book of exercises that was part of ACT -
Acceptance and Commitment Therapy, to be exact.
I remember one portion of the lessons I went through where the authors asked the reader (in this case, me) to
NOT think of a yellow jeep. They stressed that I ought to sit there for ten minutes and not think about the yellow jeep.
Well, I sat there for ten minutes thinking of nothing but a yellow jeep.
I was frustrated with myself, but in the back of my mind knew that they were trying to illustrate a point. The point they were trying to illustrate was that the more we try averting our attention from anxiety-inducing stimuli, the more prominent/present/overpowering/frustrating that stimulus will become.
The next exercise also involved the yellow jeep. This time, the authors requested that I sit there for ten minutes trying to think about the yellow jeep. They suggested picturing every facet, curve and angle of the yellow jeep - rotating the object in my mind as one would a real object in ones hands. I sat there intently picturing this yellow jeep in as much detail as I could. I rotated the jeep from all angles in my mind, examining the specific hue of yellow that it might have been painted; studying the mess of engineering underneath the jeep; picturing the wheels and how brightly its glass windows shone with reflected sunlight. I knew every inch of that jeep by the 10-minute mark!
Then the authors asked me again to sit there for ten minutes and
not think about the yellow jeep. So I did. At first, as with the first time, all I could think of was this f*cking yellow jeep! I was so pissed off LOL. But after 2-3 minutes, I noticed that I began to think about other things, and the image of the jeep gradually faded from my mind. I ended up forgetting to return to the exercise at the 10 minute mark, even! So, 15 minutes later, I read the authors' explanation of the exercise.
Their premise was that if one tries to avoid negative feelings, the feelings will grow and overwhelm you. But, despite being uncomfortable to do so, if one stops and really becomes
mindful of what they are experiencing at that moment - rotating and examining the emotion from all angles, really getting down-and-dirty with it - one comes to better understand the origins of the emotion, how it can be viewed objectively, and how doing this (rather than practicing avoidance) will lead to a decrease in the angst experienced by the person feeling the emotion. It really left an impression on me - the book was designed to address anxiety specifically, but the authors suggested that the exercise applies to essentially any aversive emotion, including fear, anxiety, shame, guilt, depression, etc.
Anyway, the whole thing really left an impression on me, and I try to practice it at least once everyday (I'm diagnosed with Generalized Anxiety Disorder, thus having ample opportunity to try the exercise
at least once per day!!).
Hope someone gets something from this.
~ Vaya