I second frozen food! It has a rep for being crap, I guess because it's cheaper? But certain things, fish and veg specifically, I've read/heard are actually better frozen as they are frozen at source so are more fresh than non-frozen?
Sorry if that's utter nonsense, the fish point came from a fishmonger so I hope I'm not talking shite 😂
Air fryer has been revolutionary - noticeable drop in electricity bill as hardly ever use the oven now, and it's amazing for frozen food.
Get into the habit of only watching the TV if you know there is something you want to watch, rather than turning it on then looking for something to watch if that makes sense?
Dressing gown over a duvet generates unbelievable amounts of heat, I swear it defies science. Learned that one as I struggle to sleep with the window closed, even in the middle of winter!
Tap water bottled and kept in the fridge is a million times better than filling a glass from the tap, and has stopped me buying other drinks in the shopping.
I'm absolutely not in the school that thinks people should have to do these things, I think it's a disgrace that people doing exactly the same work-wise as they were last year suddenly can't afford to put the heating on, but these are changes I've been able to make without feeling like I'm scrimping.