First thing I do to break the monotony is see what I have in the freezer or what is on sale (in the weekly sales ads) that looks interesting. I go to allrecipes.com and look for a recipe by ingredient: type in for example, hallibut or roast (whatever). Sort by rating, and choose something that looks good to you. I make one new recipe every week. If it's good, write it on the index card and put it in your recipe box; if it's ok but needs tweaking, write some notes in; if it's junk, toss it and there's no harm done.
I keep a posted basic inventory of what I have in the pantry, freezers, and fridge which I keep up to date so there's no wasted time there. On Friday evening or Saturday morning I take a quick look at my inventory lists to have an idea of what I've got and can do (example: I always have fettucini and alfredo sauce in the pantry....if I've got chicken and spinach in the freezer, all I need is to buy some mushrooms and some salad items, and I've got a meal that we love). Then I go through the sales ad to see what's on sale, and from those things, I come up with a general weekly menu. There's routines we have that make this process a bit easy: Mon, Wed, Fri we eat cereal/bananas, Tues & Thurs we eat yogurt. Saturdays we eat oatmeal and Sundays we have a hot meal (frenchtoast, eggs, whatever). So breakfast for the week is very easy to plug in. Lunches are gonna be sandwiches, leftovers, or some type of salad. Snacks for the boys are gonna be whatever fruit is on sale that week 4 days/week, and frozen gogurt or some peanutbutter on crackers, cheese stick, or goldfish the other 3 days. Again, easy to plug in. For sandwiches: instead of buying lunchmeat by the pound like so many people do, I buy it by how many slices I need. Instead of saying a pound of whatever, I'll say "16 slices of __, sliced thin", because I know how many sandwiches I'll be making and how many slices of meat they want on their sandwiches. That way it's not wasted or I don't end up short. It helps out to do little things like that.
For dinners, we do have routines like fish on Fridays, steak or roast on Sundays. I endeavor to make it rotate so it's not the same meat over and over: beef, chicken, fish, beans, pork...we rotate these out. I use my dayplanner to assist me with dinners: if it's a busy day with meetings, appointments, etc then it's going to be a leftover night, or easy meal, or crockpot dinner. If my son is at mother's day out and it's an easy day, I'll cook something more special and involved that day. I pull the recipe cards that I'll be using during the week and put them in the front of the box, before the dividers so they are easy to access and separate from all the other recipes; as I use a recipe, I place the card back where it belongs. If it's a new recipe, I get the family's opinion on whether it's earned a place in the recipe box or not.
Once the menu is written, I double check the kitchen (one meal at a time) to make sure I have all the ingredients for everything needed and make my shopping list that way. I go through my coupon file to see if I have coupons for anything on the list and if so put an asterisk by that item on the list and attach the coupons to the list. This sounds like a lot, but it takes 30-40 minutes to do but that's a lot less time than trying to figure something out everyday and running to and from the store all the time.
I go to the store for my "big shopping" and first half of the week's produce every Saturday morning, and on Wednesday I go for the other bits (we go through A LOT of milk, and also the second wave of fresh produce). That is all I buy on Wednesdays though; I'm pretty strict about that and not running back to the store for stuff saves us a lot of time and money. Another thing we do that is kinda helpful when it comes to produce is try to cook things with that vegetable close together. For example one day this week we have steak, roasted red potatoes, and steamed asparagus. The next day, I'll serve chicken breasts stuffed with mozzarella, rotels, mushrooms, artichokes, and 2 stalks of asparagus each, along with wild rice and steamed green beans. That way I'm using asparagus (which was on sale) and it's not gonna go bad, just sitting in the fridge all week.
For casseroles, gumbo, soup/stews, and some basic meals, I'll cook them all on the weekend when my husband is home to play with the boys. That saves me some time and I can store what we'll use for the week in the fridge and freeze extras in single portions for easy meals later. I like to buy value packs of meats and freeze them in individual portions in small ziploc bags, then freeze all those little bags in a large freezer bag that is labeled with the item in the bag and the date. That way if someone is working late or not eating with you, you can quickly only defrost what is needed.
Understanding that sometimes things come up that you can't plan for, I always keep a Stouffer's Lasagna and a bag of Bertolli pasta dinner in the freezer for "emergency" situations. Adding a can of rotel tomatoes to the Bertolli always bulks it up a little and adds a little spice that we like. It's good to have something like this on hand for a day that goes haywire. Better than eating at McDonalds, lol.
Finally, you can make friends with a pressure cooker!!! I'll buy a value pack of chicken (like 10 pounds!) and season it with Tonys and garlic, throw it in the pressure cooker and that is 10 pounds of chicken cooked and soft (easily shredded) in half an hour!!! I'll divide that up and freeze as needed, but that is 10 nearly-ready meals waiting right there: you can cook down some peppers and onions and add BBQ sauce for sandwiches, it's nearly shredded and ready for king ranch casserole, enchiladas, quesadillas, chicken and rice casserole, etc. You just add the extra ingredients (rice, fresh veg, cheese, whatever) and your meals are done so quickly. That's about all I can think of....hope it helps.