What is a good option for a tent heater?

A lot would depend on the circumstances, time and effort involved!

Best option is heat preservation! a tent is simply a wind/weather break, any heat will dissipate quick

 

if you are intending on using a tent in the winter some have stove pipe holes so you can use a wood stove in them. This is probably the best long-term option because it is a safer option and because it produces a dry heat. If you are planning on using this for short term (1-2 days) and you dont have this option then there are lots of small propane options that connect to the 1 lb bottle. This can be dangerous because it can produce carbon monoxide which is poisonous if you are going to be using propane to heat you should keep vents open to allow decent air circulation the other down side to propane is that as it burns it produces water so if you are going to be having it on alot it will cause everything in the tent to become wet

 

well I had one of those propane heaters for my tent but I don't recommend it, I burnt my tent town wth it, lucky I was not in the tent when it caught on fire. The wind blew the heater on the ground and that was the end of my first tent, but it was a learning experience.