Theoretically, if you don't waste money on gas it doesn't matter whether you go to the store once or three times a week. You just pop in, pick up all the items on your shopping list, pay and go. But, as we all are human, in practice going to the store more often usually results in spending more money, because you spot "just this one thing" you must have (though you perhaps wouldn't have even thought about it if you had not seen it). Then some things are on clearance so you buy heaps, and later it spoils, or you use it too lavishly. In short, the less often you go shopping, the less money you will spend.
Plan ahead. Plan your meals - at least the more important meals of the week. Don't forget to make alterations when you know you are going to entertain, go on a vacation (so you won't buy what will spoil while you are gone), etc. Then make a shopping list accordingly.
Stick to your shopping list. Of course there are some bargains it would really be a pity to miss. But most of the "great deals" are not so very great or necessary. Good deals on unhealthy stuff in a box are not really good. Same goes for good deals on stuff that will just clog up space in your home.
Improvise. If you intended to make, say, avocado dip for entertaining but found out you ran out of avocado, you can quickly run to the store and buy avocado, and perhaps ten other things on the way. Or you can take a look at what you do have, and alter your plan accordingly. If you have cream cheese and tomatoes, for example, you might make tomato salsa and/or a cream cheese dip.
And in conclusion... just love this: