When my mare got wound up it was like sitting on a pneumatic drill - horrible. I just had to push her on until she settled and trotted properly which could take a while sometimes!
My horse is mechanically lame thanks to a broken piece of bone from his hock, although not now in pain. It has made his trot feel horrific (and me worry that if anyone sees it I'll be reported to the RSPCA) but he is still as keen and forward going as ever so my solution has been to stand in the stirrups as if galloping.
I'm hoping you don't all think I am horrific for riding a lame horse but he is sound in walk and canter and I have got the vet's go ahead. He loves his work but obviously we will never be able to compete again.