I consider myself to cook pretty much everything from scratch with the aim of avoiding UPF.
I use the vague rule of "was this in my great grandmothers kitchen" and if yes then im ok with it.
I use dried pasta, and rice and tinned tomatoes / tuna / sweetcorn / beans / chickpeas.
I consider making custard with custard powder, milk and sugar to be cooking from scratch, while i understand it should be egg yolk / sugar / milk and cream.
We grow a LOT of fruit and veg in our garden which we use when in season, and freeze what I can, and I have a full herb garden, but also a cupboard full of dried herbs / spices / curry powder / soy sauce / selection of vinegars.
I absolutely buy whatever fresh fruit / veg / meat / fish I need in additon to whats growing.
In September my glut of tomatoes makes quite a few batches of "tinned tomatoe" equivilent, but probably only 8 tins worth.
I basically buy dairy products (mainly organic, as contain less rubbish), fruit, veg, meat, fish, basic tins (as above) flour, sugar, cocoa, dried fruits, nuts, seeds, less processed cereals (oats / weetabix), pasta, rice, cous cous, sharing packs of "quality" crisps with ingrediants i have in my kitchen, "good" chocolate.
I buys jars of pickles (beetroot, onions etc) and also things like "quality jam", "local honey", and pickles and chutneys. (about once a year i might make my own jam / chutney).
I read labels and have, for example cadburys drinking chocolate powder, hellmans (full fat) mayo and heinz ketchup, colemans mustard etc in my fridge (which contain far less rubbish UPF ingrediants than own brands, and which my great grandmother WOULD have had in her kitchen)
I use freshly ground pepper and sea salt, and olive oil in cooking
I buy large gammon joints which I slice myself instead of packs of ham and would always make my own egg mayo / tuna mayo sandwich filler. (eggs mainly from chickens kept by my family)
I also buy bread products (which I know are really bad for UPF) but i do make my own bread and pizza bases, and foccacia, as well. I buy the odd pack of biscuits and cereal bars, but i make the vast majority of cakes / biscuits / flap jack etc from scratch (with real, unprocessed ingrediants, not low fat spread and chemical sweeteners)
I have crackers and savory biscuits available to go with cheese in my fridge.
I buy organic ice cream which has far less rubbish in then cheap ice cream. I buy very little frozen food beyond peas and frozen spinach, but my freezer is full of fresh meat and fish that I have frozen myself (as I buy in bulk) and portions of home made meals, and also things like home made stock.
I sometimes buy high quality farm shop sausages
I have a few jars of pesto for a super quick tuna pasta pesto
I would NEVER buy breaded products or nuggets, or potatoe based things such as waffles or frozen chips (I make my own by slicing potatoes), or ready meals
I absolutely consider myself to cook from scratch.... because I use real ingrediants to create real delicous food.
Typical breakfast is home made porridge or eggs with toast (sometimes homemade bread but sometimes shop)
Lunches will have home made sandwich fillers, often home made bread, decent crisps, fruit, salad etc
Dinners are ALWAYS home made cooked from scratch, and i make a couple of "puddings" a week (served with cream, custard made with custard powder or organic ice cream [I do have an ice cream machine and occaisonally make it from scratch]. Or yoghurt and fruit, and we normally have some sort of home made cake or biscuit in the tin, as well as a full fruit bowl for the odd snack.
I make my own fizzy water with a soda stream which I may (or may not) add to organic cordial (not home made by me), and my children mainly drink water.
I do buy tea bags and coffee pods and cafetier coffee too