Make sure your space heaters have an emergency shut off in case they tip over. Only use the fuel recommended by the manufacturer. Never refill a space heater while it is operating or still hot. Refuel outside, away from the house.
Space heaters need space! Keep combustibles at least three feet away from each heater.
Carefully follow manufacture's installation and maintenance instructions.
Do not use the oven to heat your home. It is a fire hazard, and it can be a source of toxic fumes.