What is the best way to seal a door to a room?

What's the best way to seal the light coming out from underneath a door? I've found weatherstripping to be very helpful for the rim of the door, but having issues at the bottom.

Currently I'm simply bunching up a towel by the base of the door to block incoming/escaping light. But would like to find something a little less obvious.

Thanks!

get one of those draft guards. they are like 10 bucks on ebay and the totally seal the bottom of the door. or you can install a door sweep which is not recommended on carpet.