Mamacita:
I did a search on "how to pound chicken" here is some paraphrasing of info I found that makes sense to me since I have problems with the same thing..(crime Scene

)
Apparently we are hitting it too hard too early. So, here's a good way
Get a gallon sized, freezer weight, zip-lock bag. Cut off the "zipper" of the bag. Cut through the entire length of the closed edge of the bag to form a pouch. Place newly formed pouch on a clean cutting board and lift the top side up to open. Place chicken breast or breasts (just don't over crowd), into the pouch. This action will help the chicken "slide around", so you don't rupture it. Which I believe is how the chicken massacre happens Mama

Start at the thickest part of the breasts using the least textured side of the hammer, pound gently using short strokes to get it started. Let the weight of the hammer head do the work. Pound in a slight circular motion and outward to the edge of the meat. Don't beat it to death. Work slow..no need to pummel it