I also SAH, and while the cooking doesn't bother me, the cleaning gets old. So I've been fixing lunch at the same time I fix breakfast, and I make snacks once a week.
I peel and chop carrots, celery, and peppers all at the same time, and put them in these
. (Wal Mart has their own version for much cheaper... I should have waited... grr.) I might wash cherry tomatoes and put them in one, too. I don't do cucumbers ahead, though, they get funky too fast. I mix up a couple small containers of dip- very often just low fat mayo and Italian dressing, stirred together. DD likes a little ketchup in hers, makes it more like thousand island dressing. I'll also make granola or trail mix, and a dozen small containers of homemade custard style yogurt or pudding. I'll take a loaf of bread, sliced, and make the whole thing into PB&Js, which I then put in fold top baggies and put them back in the bread bag, which I then freeze. You can take out a sandwich, put it in the toaster oven/microwave for one minute, and it's nice and warm, which is a yummy way to eat PB&J. We also usually have fresh fruit on hand, or, as back up, canned peaches and pineapple. I'll also cut some cheese up, and hide it in an opaque container so it doesn't all get eaten right away. I try to have little melba toasts on hand to eat with the cheese.
Does this save me tons of time? No, not really. But it saves lots of cleanup, since I just do one big cleanup once a week and don't have dishes staring at me after every time someone gets a snack.
Today, while I was making oatmeal and coffee, I made salmon salad (from canned salmon) and pasta with peas (thank you, Clara on YouTube!) for lunch for today and tomorrow, since I know we'll be busy tomorrow. Just spread the bread, or put the little pot on the stove, and it's done. No thinking, fewer dishes at lunch time, and not much more clean up at breakfast. While I was cooking, I figured out what we're having for dinner. I got the soup in the crockpot, sliced and buttered eight peices of bread, and sliced cheese. (We are having tomato-basil soup, grilled cheese, and dill pickles for dinner.) My cooking today is all but done, and other than a couple plates, three bowls, the grilled cheese pan and turner, and some spoons, all my dishes for the day are done (we use water bottles, so no cups.)
Getting it all done and out of the way in the morning helps me get other stuff done during the day, and not feel like a martyr to the kitchen. Plus, after dinner I'm tired, and I don't want to tackle a giant dinner mess. A small dinner mess I can usually handle.
This isn't about saving money, per se, but eating at home saves money, and this helps us to eat at home.