Here's my method. I do online shops with Tesco once a fortnight and top up with fresh fruit/veg if needed
About a week before I want the shopping, start an online order. Go through favourites and look at special offers and put a basic basket together based on rough ideas of what I fancy/what's on offer.
At some point during that week, check through cupboards and freezer and see what needs eating up, or get further ideas for meals.
Write on the calendar what we're having for dinner every day. I have one of those family calendars with columns, so DS gets a column, I get a column and another one is dedicated to food!
I only plan dinners and don't plan every dinner. For example, I don't eat with DS twice a week, so we both have leftovers that night.
When I plan, I try to include one or two things that can be batch cooked, like chili or bolog. Meals like use a lot of fresh veg, like stir fry are scheduled for soon after the shopping and then towards the end of the fortnight it's more meals that can be made with store-cupboard or freezer ingredients. I also plan to use up leftovers or things that have been batch cooked for the freezer so things get rotated on a regular basis. I also include things like quiche or pizza in the shop which are not planned for, so that there's always a standby in the freezer.
The actual rootling through the cupboards and planning the meals takes about 15-20mins. The online shopping takes longer as I do several updates as I think of things that we need. I also like to do a thorough trawl of special offers! I quite enjoy online shopping and will do it when I'm watching TV in the evening, so it's not a chore for me.
DS and I both take lunches to school/work so I just make sure we have bread and various sandwich fillings in as well as plenty of fruit. Snacks are fruit, biscuits, sometimes crisps, which I just buy as needed.
As well as cooking extra for the freezer when I'm doing something like chili, I'll also batch cook just for the freezer when I have a chance. Often this is soup to use up veg or something like dhal that takes a while to cook but is very useful to have tucked away in the freezer.