I always rub gently between the shoulders starting from their head towards their bottom.
If they are okay with it then in the same downward motions on their neck and down the back to their hips.
Never anything like you'd do on a person for a deep tissue always going from head to tail never return or press forward from tail to head.
Soemtimes mine just walk away or do that bottom to my leg because they just want to be petted or scratched.
I should make a video sometime with what he showed me...
here I just google and watched a few this one is great and a how to by a vet.
See how once he goes past the neck he never pushed the muscle toward the head always down from head to tail.