We have this issue in our house - a lot. It's 6 pm, J and I are both starving, and yet we have no food thawed out, the left overs are bad, and no plan for dinner. So we make it work by going out to eat - a huge killer for our already tight budget. We have implemented a system at our house to make grocery shopping easier, decrease the meals we eat out, and make the most out of the food we do buy. If you take your lunch to work, you can even take this a step further by figuring out how you are going to dole your leftovers out over the week for lunch.
1. I have taken this idea from a sweet girl I know from a Facebook group for Erin Condren fanatics. I created a page of quick meal ideas (my "meal reference") that I refer to when I get stuck. I have organized these by categories: main dishes, crockpot recipes, sides, and recipes to try (for when I stumble across that amazing-sounding recipe on Pinterest and want to actually remember which dish I pinned). If you have a picky kid, make a list separate for them and add to it when you find a new food he or she likes. The possibilities of your menu reference are endless! I even created on specifically for parties, dividing it up into the following categories: appetizers, sides, salads, finger foods, dips, and main dishes.
3. Once I get to the point where I am ready to decorate my week (see how I do that here!), I write down each meal on a sticker and stick it at the bottom of the page on the lined notes section.
4. I then transfer the meal plan to our menu board on the fridge. I ordered this off of a discount website (jane.com). The original company was Lovey Dovey Creations. This way, if I am at work with my planner, J knows what to thaw out, cook, prepare, etc.. We often use the left overs for lunch the next day if we can. Sometimes, we simply plan to make less of a meal if we are trying to cut down on the amount of leftovers we have (like if we are leaving for a trip later that week).
I hope this has inspired you to get to meal-planning! I plan weekly so we make weekly trips to the grocery store. However, I have made monthly meal plans before (it just got a bit tedious for me). The great thing about this system is you can use all (or none, or some) of what I do. Let me know how it works for you!