Chinese tui na (push and pull) practitioners have listed several specific facial muscle exercises for the rehabilitation of facial weakness.
(1) They recommend applying heat pads to the face, like soaking a towel in hot water and then holding the wet hot towel against the face.
(2) Massage the face with counter-clock-wise motion with the palm of the hand.
(3) Acupressure on certain points or tapping some points on the face. In my acupressure class, I taught my students to tap on certain points on the face and to rub and push certain facial muscles. (3-1) Push the thin muscle that is on the cheek bone upwards. (3-2) Tap the thin muscle that is on the cheek bone. (3-3) Tap the soft area of the cheek. (3-4) Tap the area in front of the ear where the upper and lower jawbone joints in the sides of the face. Tap this area on both sides of the face as hard as one can. (3-5) Tap the cheek muscle that is right next to the nostril. One should be able to feel the tap on the upper gum. That tap will also enliven the inside cheek muscles.