Plan your meal the night before by taking any frozen meat out of the freezer and put in the fridge Gather all your ingredients the night before to make sure you have everything. If you do this early in the evening, you may be able to get out to the store to shop for missing ingredients. If not, be prepared to go out on your lunch break the next day or on the way home. I had a slight problem with stopping on the way home. I had a deadline for picking up the kids at daycare so I had to pick them up first and then go to the grocery store. It can be a trying experience with kids in the grocery store. They see something they want and you don't choose to buy it. Get ready for a battle.
If possible, try make part of the supper the night before. Spaghetti sauce is always better the 2nd time round! When you arrive home, boil your noodles while you reheat the sauce. Chili is good the next day, but be sure to use a cover when re-heating with the microwave because the beans explode. Casseroles can be prepared the night before and popped in the oven when you get home.
You may consider using the automatic start feature on your oven. I'm a little hesitant to use this with fresh food because it will be sitting in the oven for several hours before the oven turns on. It works well if you put frozen food in the automatic oven, so you could prepare a casserole well in advance and put it in your freezer.
If you don't have a microwave or crockpot, consider buying one. Most families have microwaves and they are wonderful for thawing and reheating or cooking certain foods from scratch. I use mine for rice or pre-packaged noodles/potatoes & sauce and it turns out perfect! If using a crockpot, put all the ingredients in the crock the night before, then store in the fridge overnight (I have a 2nd fridge in the basement). All you have to do is plug it in the next morning. I have two settings on my crockpot and the low temperature will usually cook the food in 8 hours. The fast one will usually have the food ready in 4 hours.
Have a "cooking spree" on your day off. Things that are easy to make ahead are casseroles, sauces, meatballs, hamburgers, stews, and lasagna. You can store the made-ahead dishes in the fridge for use within a couple of days or put in the freezer for longer storage.
Make double quantities during mealtime preparation. For sauces, I always double the recipe and freeze the remaining half or put it in the fridge for a day or two to give the family a rest or use it in another dish. Spaghetti sauce with noodles for one night and use for a pizza base another night. I figure that while I have all the ingredients out and the pots in action, it doesn't hurt to make more. I do my shopping with double quantities in mind.
Do up a shopping list with meal planning in mind. Sit down and figure what you plan to cook for the upcoming week and shop accordingly. I have a small whiteboard in my kitchen and I write down items that are getting low or I've run out of. I add this to my list too. When my kids got old enough to write, I welcome their entries on the whiteboard. They help me by writing what they used up and requests for my next shopping trip. Not all their wishes are honored but it does give me an idea of what they want to eat. Cereal is a hard one to figure out. There are too many to choose from and what they like one week is not what they like the next.
I find that if I'm not organized, half the stress is worrying about what to serve rather than the actual task of preparing the meal!