Having a grocery list is probably the most important of these methods. If you stick to your list, then you’re going to have zero unanticipated expenses. I use a to-do list app on my phone, but some apps were made literally for a grocery list.
Name brands honestly are such a scam. You’re paying for a brand, and that’s it. You can’t tell the difference in quality, and if you say you can, you’re lying.
Ibotta is a great coupon app to use. Many weeks I’ll only get $.10 or $.20 back, so effectively nothing, but sometimes, I’ve found myself getting $5-$10 back because I’ve had to buy diapers and a few other items on promotion.
Going along with understanding unit cost, do not be afraid to buy in bulk. Buying in bulk is one of the best things that you can do to take advantage of deals and allow yourself less of a chance to run out of items.