The videos/advice I've seen is for the yips on short putts, but I've got a problem on mid to long putts.
Any advice or links to good vids?
Without seeing your stroke I would guess that when you have a putt longer than 10 ft, you just "hit" it harder. Same length backstroke but you just add more speed on the thru stroke. Very tough to control distance and direction when you do that.
Good thread to check out
So I would say keep the tempo the same as you would on a 5ft,10ft putt but just make a longer backstroke. Make your stroke more like a pendulum and less "hitty."
Like @iacas says in the thread.
"Your putter should be at peak speed or even slightly decelerating when it hits the golf ball. The thought that you want to "accelerate" into the ball has ruined many people's tempo."
I used to be really terrible at long putts. Like, awful. Not sure I would describe it as the "yips," but it was definitely a mental struggle, not a physical (stroke) problem.
What helped me the most is remembering the goal is to get it close, not make it. I realized that I was trying to drain them and that was causing me to tense up. It's wonderfully freeing to think, "OK, I just need to get this within 3 feet." That gives you an area of almost 10 square feet.
It helped so much that now I would say lag putting is one of my strengths.