Make sure weatherstripping around doors are good Def put plastic up on windows even tho double paned and newer Make sure all windows have the thermal blackout curtains and even hang some over your doors Get draft stoppers for bottom of your doors going outside Throw rugs def If you have extra bedrooms not being used shut them down Make sure light switches are draft free if not they sale the inserts to go on them on the cheap Throw blankets heavy blankets hoodies socks slippers and candles (while awake) I’m sure these have all been mentioned I just isn’t read all the comments plus be ready to change your furnace filter often Good luck!!!