Check out the specials in shops from catalogues and mark those of interest. Only buy things on special if they are products you are actually going to use it in the near future. It’s not a bargain if you are not going to use it.
Shop from a list, written out at home after checking the pantry and meals planned to see what you will need.
Read labels carefully, especially if you have allergies to certain like sulfites or preservatives.
Don’t assume low fat means it is healthy for you and low in calories. Often when they take out fat they add more sugar and so calories actually are increased.
At one stage because of a skin problem, I was told to cut our salt from my diet. I told the health expert I never used salt not on food and not in cooking either. But it is the hidden salt in products that is the killer. Take any can or packet of food and check out the sodium and you will see exactly how much salt is really in your diet. The way to deal with that is not to use processed products but always use fresh. However this is not always practical. So for example if you are using canned lentils, corn, beans, or other canned products along these lines, rinse them before you use them. That way you will get rid of an excess salt.
If you are gluten free don’t a assume wheat free means gluten free. Gluten is also in other cereals such as barley rye, and oats so stick to corn and rice based flours or some of the others like potato flour or those mentioned on my blog. On that note, glucose syrup on products like most sweets and many chocolates and dessert products is almost always from wheat, unless it specifies it so from corn.