A lot of the supermarkets and also Superdrug and BHS sell off their last seasons jewellery at half price or less, so that they can get their new seasons stock put out. I got a bracelet for a quid once, you couldn't buy the beads to make it for that. Possible gifts/stocking fillers?
Starting a stock of food and stuff for Christmas: pretty much anything in tins, jars, bottles, packets and dried. If you like to bake you could get flour, sugar, dried fruit etc. in advance. Longlife items in cartons like milk, fruit juices, custard. You can use longlife milk in cooking, e.g. in bread sauce, brandy sauce or custard. Things like stock cubes, cooking oil, ketchup, pickles, soy sauce, curry pastes. I usually get in extra foil and kitchen rolls, and loo rolls too (if you have the storage space it's worth doing and also if you are expecting a lot of guests) Dried pasta and rice are good to have. Alcohol and soft drinks, tea, coffee, hot choc. Biscuits and crackers for cheese, crisps, nuts, snacks, sweet biscuits. Tins of tomatoes, soup, beans, fruit cocktail, chestnut puree etc.
You might want to add in as applicable to your family: pet food, baby food and milk, nappies, toiletries, and cleaning materials, especially something that will get stains off carpets and upholstery! Look out for special offers or vouchers and buy when you've got a bit of spare cash.
Also remember medicines, both prescription and over the counter. Painkillers for all age groups, and get prescriptions in good time before Christmas, don't leave until the last minute.
I find it helpful to plan menus when you know what you're doing for Christmas or how many guests you're having, so that you can be sure of buying what you need for the meals, and also can cook some things in advance for the freezer.
Hope this helps someone!