All you need is practice. I tried to say words to help but it didn't, I would practice when ever i drove. When you hear the sound that sounds best to you just remember what postion it was in and how you huffed. I put it mid in my mouth and push up on my throat(like a gag almost) and huff air to make the sound. I guess when i started i would say "rock or rocks" but went with what sounded best. Hope this helps.