Dry-fire at objects on the TV screen before they disappear. Just make doubly sure the gun is unloaded so you don't pull an Elvis.
Guess the ranges of random objects in different environments and light. Check your accuracy with a rangefinder—and watch it improve.
Use dummy rounds to practice blind reloading your rifle's magazine from your recliner while watching the idiot box. So I watch a lot of TV, O.K., but I'm really fast at reloading.