I almost never buy the big tins of biscuits or boxes of sweets. (Except a tub of scots clan - which we eat over the course of a few months).
Instead, I make sure I have a good few packets of nice biscuits that we like, a few different types, and open a few of those to make a nice selection on the plate. And as I keep them in a proper airtight box, they stay fresh. If we have loads of visitors, we open more, and if we have fewer, we only open 2 or 3 - and we will get through those over maybe a fortnight even without help. But we don't then overindulge on them.
Not exactly frugal - but we do buy 1 bag with about €10 worth of Leonidas orangettes as a family treat. We all love those, but we don't then get a load of other chocs etc, as they wouldn't be eaten. So we probably spend about the same, but get something we really enjoy as a treat, and don't see the same results on our waistlines if we'd bought big tubs of Roses or QS.
I have HM mincemeat maturing in a large jar, and have been saving old jam jars to pot it up in a few weeks. Some of that will go in hampers for presents. I am planning on adding some mulled wine sachets to that, which I make using large packs of spices from the Asian Supermarket, and use more of those for a hamper for someone else big into their food so nice spice mixes (for curries, pulau rice etc) are very well received.
Some years I am good at crafting presents - 1 year, all 8 Aunts and Uncles each got a different scarf that I knitted (colours and stitch patterns suited to each), and I've done things like sewn tree decorations from scraps and a few decorative elements which look fab (I keep the ribbon that clothes labels are often attached with and use those for small items like these), and give a handful as a gift to some people. Time has been against me though for the past few years, and I have a stash of raw materials in the corner shaming me....
I do tend to put money into savings for the big food shop. The €2 stamps on the card, which most supermarkets give you a final stamp for if you fill it (it costs €98 to fill but you get €100 to spend) - it may not be much but 2 of those are a help. And I save my points/money off vouchers as well. My big food shop is as much about restocking cupboards that I run down in the autumn though, to clear out old stocks, and take advantage of many special offers (% extra free, BOGOFs, etc) on things I would buy anyway. So it's always great to stock up with enough mayonnaise to get midway through summer BBQ season, and ketchup to deal with winter's oven chips dinners, and lots of jars of sweet'n'sour sauce for quick midweek dinners rather than leftover turkey solutions.
The aspect of my food shopping that doesn't fit that is the baking cupboard, as I tend to restock that in the autumn when the pre-Christmas baking specials are on.