Buy some items in bulk and some in small amounts!
A huge reason people spend to much on groceries is because it goes to waste. I usually would grocery shop once a week, and here is pretty much how it would break down:
Every 2 months:
The ingredients for things that would last me several months that I didn't need to buy often but were essential for cooking!
Truvia packets (for my coffee)
Frozen fruit - I get the really large bags and I typically get the mixed berry and the peaches/mangoes one. They last a long time and are great with almond milk for smoothies
Every 2-3 weeks:
The things that would typically last me for about 2-3 weeks are the essentials.
Cereal - Cheerios, Bran, Special K, Rice Chex, Kix. Pretty much any whole grain cereal on sale that I could mix with fruit.
Bread - Double fibre English muffins or whole grain sandwich thins
Almond Milk - Typically I buy the generic store brand because it’s cheapest. If you like regular milk, stick with low-fat!
Greek Yoghurt - The big container of non-fat original flavour
Eggs - 18 pack of cage-free
Canned foods - I typically buy black beans and green chills canned to make with omelets and quesadillas, and I buy chickpeas for salads.
Nuts - For snacks and for salads
Once a week:
The things that go bad easily or run out often. Buy them in small amounts to avoid them going bad.
Fruits and veggies - If you stick with fruits and veggies that are in season, they are going to be your cheapest bet. Get fruit to mix with cereal and yoghurt and get veggies to put in salads and other dinners, but look for the ones that are on sale and in-season.
Salad mix - Whatever lettuce you like, there is usually a lot of different kinds, and typically the ones in the plastic box containers are the most expensive. Look around to find the cheapest option.