The secret to saving on your grocery bill is a well stocked pantry. Essential, spices, rice, potatos, couscous, pasta can be bought in bulk and on sale. If one remains stocked there is always a meal on hand. I buy at specialty stores like Sprouts, Sun Harvest and New Flower becaue they are all close to my home and are having price wars. Their marketing gives me great deals. I look at sales fliers, which are online too, and see which one has the most of what I want on sale. That being said I don't make all my purchses there. HEB is my main stay for houshold items and they have the best prices overall. We shopped at bulk stores for a while but decide that the items there were mostly processed and lead to too much waste.
The biggest mistake I make is to shop without a list. My list consist of meals, necesary items and household items.