Here’s a cheap and quick way to save money and energy.
Stopping drafts is an easy way to reduce your heating bill in winter. If you own your home you’ll probably want to add weatherstripping as a permanent solution, but if you’re renting or low on funds you can re-purpose a 6ft length of pipe insulation available for $1-1.50 at any big box home improvement store into two door draft guards.
The only disadvantage is that the pipe insulation cannot be used on windows unlike the Door Draft Guard.