I write my shopping list and stick on fridge and tick off as I go - lovely feeling seeing everything crossed off just before the big day.
Buy food in advance as it's less stressful and cheaper with offers etc - non perishables though like crisps and nuts.
I have a Xmas cupboard - all food in one box to stop dh and ds busting it into it before the big day and presents, card and wrap in another box.
I also stick my present list on fridge - name and then whatever I pick up for them I write it next to their names so I can see what everyone has.
Very boring but when ds opens presents under the tree I have my notepad ready and jot down who gave him what for thank you cards. I always write them 'from him' and personalise the cards - you can get some great, cheap ones from ebay that you can stick a picture of ds in opening their presents under the tree on Xmas morning.
Second class stamps for all cards and thank you notes.
I have ordered all my food and bird to be picked up and noted down pick up times - will send dh to pick up one load to ease my workload.
Lay table NIGHT BEFORE - glasses, napkins everything!
I do order all my cards and wrap reduced on Boxing day sales online - saves time and money.