Old apartment with poor insulation and costly electric baseboard heaters… what are some things you’ve done to insulate and save money?

Title, basically. I’ve read a few posts on here that say the usual (window film, curtains, making your dogs lay down around you lol). A lot of the advice seemed more geared toward houses, so I figured I’d ask about apartments specifically! I’ve put plastic on my windows and have curtains now, but I’m still so cold. I’m looking for any recommendations on what else I can do to help the apartment retain heat better. Give me all your best tips - from quick fixes to major changes.

Thanks!