It doesn't have to be complex, and you don't have to stick to it religiously.
I have a blackboard that I write mine on, but when I first started I had a spreadsheet, then I wrote in a notepad, then on a back of an old envelope.
Here's a simple example of a meal planner. (You can get as fancy as you want - doing a carb/protein breakdown kind of thing!).
|Saturday||Picnic in the park (sandwich)||Egg fried rice with bacon|
|Sunday||½ out with her dad. Me - lunch with friends||Roast chicken (freeze left overs. Check if there are any frozen roast potatoes.)|
|Monday||Work||½ at her dad's. Me - something from the freezer|
|Tuesday||Work||Cheesy Tortilla Triangles, cherry tomatoes & soup|
|Wednesday||½ at preschool. Me - smoked mackerel and quinoa||Rice noodle soup and veggies (left over chicken from freezer)|
|Thursday||Pasta bol (from freezer)||Fish pie|
|Friday||Chicken wings & pita pizza||Spanish rice with veggies|