I once played 9 with a very good player, both of us with lefty clubs and was completely rubbish until my friend said to me, in effect:
"You were a tennis player, weren't you? If so, just think of hitting a right-handed backhand with the left arm following and stabilising."
This worked, and more serendipitously, got me to think of using more left arm and less right hand in my right hand swing. That worked too, and helped me get from an 8 to a five.
PS--I remember one of those silly season events 20+ years ago where one of the "challenges" was a closest to the pin on a 150 yard 3 on a very forgettable course. VJ Singh won that hole with an 8 iron to 8-10 feet (those were the goodie olde days where an 8-iron was the go-to club from 150 for the pros.....). After confirming that he had won, VJ asked the lefty in the group (it was either Weir or Mickelson) to borrow his 8 iron, and then smoothed a shot to 3 feet.
Those guys are good!