I know it lacks spontaneity and sound pretty dull, but it really helps regarding the bank account and general effort.
When creating your dinner menu, use recipes that involve ingredients for multiple meals.
For example, using guacamole for burgers, avocado chicken and maybe even nachos. Or buying a big pack of mince to make a shepherd/cottage pie and meat balls or burgers.
The plan does not have to be day by day and you may shift it up a bit to suit your schedule but thinking about it will make a mole hill out of the mountain that is cooking and help everything slot into place.
In the future, I will come up with ideas for weekly meals as well.