Blankets should go under your duvet. Duvets works by holding air in them, if you squash them flat with a blanket they work less well.
Don't put fleece up as curtain lining or curtains, they're not fire retardant
Spray your window panes with a mist of water and put bubble wrap over the panes. The water makes it stick. Triple glazing for pennies
Extra curtains over your front and back door.
Measure up the space and set an alert for second hand curtains on eBay.
Keep tinned potatoes in the cupboard -a potato is a more nutritious staple than rice or pasta
I have lots of old flannels and no kitchen roll
Water, with a little fairy liquid and zoflora in a spray bottle, cheap degreaser and disinfectant in one for surfaces (don't use zoflora on paintwork)
Old fabric can be made into rag rugs to cover cold floors. Lots of YouTube on how to.
Takes time but can be made to fit your space. (Planning this for my kitchen)
Get a pet insurance with a free video consult service. Can sometimes save you a visit.
Many Pets have it.
If you can, keep paying even a basic insurance for pets and get regular meds from one of the online pet drug places. It's time consuming but worth the saving if your pet takes a few regular meds
Quit adult Christmas gifts
Sign up for the Libby app
Talk to family and friends about it all, you may find ways to co-operate on purchases and make savings. I would swap ironing for dog walking for example.