A friend makes little hot chocolate or cake jars
Pop in ingredients like flour, cocoa powder and top with some chocolate chips, or hot chocolate powder and some marshmallows and you can fill old jam jars or anything like that and wrap a ribbon on. Include the recipe if it’s a cake and what they need to add. That’s really cheap as you can make a few with one bag of cheap flour etc. You could also do s'mores/toasted marshmallow kits with a candle and marshmallows, add chocolate and biscuits if you can be bothered. Again just pick up one large bag of marshmallows and some kebab skewers and cellophane and a ribbon. You could do a gift for everyone for less than £5 total probably.
if you put two candy canes together into a heart shape, and pour chocolate in the middle, add some sprinkles or whatever you like, that’s quite a nice little gift.
taylor Swift style friendship bracelets, depending on your demographic. They can all say something fun on them, or a song that reminds you of them.
go to b&m or tk maxx and buy some cheap (but tasteful) frames, and print out a picture of their family or something nice they may have sent you this year.
a nice hand sanitiser is always useful as far as I’m concerned and fairly cheap to pick up
home made fudge is easy enough
hobby craft and pound land and lots of other places often have very cheap ceramic Santas and things with paint, or wooden ones and some felt tips, if you have any young guests and it gives them a thing to do on Christmas Day when you need a minute.