Strengthening: rest forearm on thigh in sitting with wrist over knee, use a 2-3 pound weight
1) flexion (palm down)
2) extension (palm up) if brings on symptoms don't go through full motion
3) ulnar deviation (thumb up)
Try these 3 positions moving hand up and down against gravity. If you have pain on the palmar surface of wrist or numbness do not continue (or try lighter weight or limit range of motion). If everything is ok, you can add weight especially with extension.
Carpal tunnel is sometimes caused by wrist flexor tendon thickening, so it is a good idea to stretch these. Start with elbow bent and palm facing up, then bend your fingers toward floor until stretch is felt in forearm or wrist (again you do not want any hand symptoms). If you cannot stretch without pain or numbness it may be too inflamed; then just go through painfree range of motion until inflammation is decreased and you are able to stretch. You can also try straightening out the elbow to get a further stretch.