A suggestion for christmas 2019, Park Hampers are an excellent way to save for christmas. You decide how much you can afford to pay each month, pay by DD then at the beginning of November, you get that amount in gift cards or vouchers, too many to list here.
Alternately, Amazon have a similar scheme where you pay a set amount per month but you can only spend it at Amazon on line.
Local supermarkets sell gift cards to a wide variety of stores, including their own starting a a very reasonable £10 per card. Maybe adding one or two to your monthly/weekly shop and saving them until Christmas might be an idea.
I live on a very restricted budget and use these methods to pay for christmas and birthdays. Charity shops after Christmas are always full of gift sets and unwanted gifts, not to mention sales. This means you never, or rarely, need to pay full price for gifts.