I'll sometimes do a day where I blitz it, making a few different things and freezing.
But my general approach is little and often.
So I will make a sap bol sauce, but do enough for at least 2-3 family dinners in 1 pot. The prep is not that much different - and I will use the food processor to dice up the onions (as a few in the batch), and then dice up extra veg to "hide" in the sauce (carrots, mushrooms, peppers, courgette etc), as I have the FP out already. I try to do this the day before I plan to eat the sauce, so after dinner on a Monday I might make it for Tuesday and then it has time to slowly cook down properly, and I will do the cooking before doing the washing up for both the Monday's dinner and Tuesday prep.
Then, Tuesday night, in from work, boil the kettle and start pasta, and put enough sauce for 1 night in a smaller pot to reheat. I generally leave the "tubbing up" until then too (well, after dinner again) so it had time to cool properly on Monday night. I usually freeze in washed plastic takeaway containers, as 1 person portions, and mark with a sharpie whats in them. That way, they will stack well, defrost slightly quicker (as smaller portions) and I can decide if my freezer meal is to serve 1, the whole family, or includes guests - and take out the relevant number of portions to defrost.
I try and take out things from the freezer the night before eating them also - usually after dinner - and I usually leave them defrosting overnight on the worktop and then put into the fridge in the morning. Sometimes I am organised enough to take them out either 36 or 48 hours in advance (so 2 nights before, or say Tuesday morning to eat on Wednesday night) and defrost in the fridge.
Some dinners do well as leftovers - mac'n'cheese (which is full of ham and veggies too) is great served hot and fresh, and leftovers get frozen to reheat (with grated cheese over the top) as a pasta bake.
And I am learning about having easier ingredients too - like dicing up chicken breasts before freezing so that they can go straight into a pan from the bag after work, not need dicing when I am tired and people need food NOW! And also about pre-marinating them too - I have some lemon and garlic chicken joints in the freezer at the moment, that I can defrost and throw straight in the oven - meaning I can even just take them out on Wednesday morning for Wednesday night dinner, and defrost them in the cold oven set on a timer to have them cooked when we arrive in home (along with some baby potatoes already oiled and seasoned for baby roasties).
If I have leftover cooked meat, say from a roast etc, I will freeze that too. It can be really handy for mixed meat Chinese stirfries etc to add to fresh veg, or to make leftover type meals midweek.
Some nights (weekends always!), we have a family curry feast. It is a combined effort in the kitchen, over the course of the afternoon at a relaxed pace. We make at least 2, maybe 3 types of curry, reasonably large batches of each. I'll throw a decent sized tray of Bombay potatoes in the oven. We will also make some rice, and if I am feeling really energetic, some naan bread (really energetic!). We enjoy a proper feast dinner that night, and then have plenty of leftovers to freeze for other nights. And by freezing in single person portions, when we are having a curry night some midweek night, we might all have the same, but if DD fancies one thing and DH another - that's not an issue (or we can reheat 2/3 different things and put them all in the middle for everyone to share). But it's also handy when there is only 1 person at home, or we are all passing through at different times.
Other things can be to make up a batch of savoury mince, and even if you don't have mashed potato that night with the first lot, freeze the leftovers as they are. Then another night when you ARE having mash (eg with sausages and fried onions?), peel enough potatoes for 2 nights at once (it really doesn't feel like 2 nights when doing it at once compared to doing it individually 2 nights in a row, only getting out the tools and potato bag once etc). Morning of sausages, take out the savoury mince from the freezer. After sausages dinner, put the mince into an ovenproof dish and cover with "leftover" mash, and tomorrow's cottage pie is ready for the oven.
I look on it as doing a little extra work at a time when I have the time/energy to do it (weekends, some evenings AFTER dinner, etc) that then minimises the work I need to do to get tasty food on the table when its needed after work and school midweek when everyone is starving, energy levels are low and often someone needs to go somewhere afterwards (and also reducing waste). So taking out the food processor for a few jobs makes that washing up worthwhile. Peeling double quantities of potatoes takes a few minutes longer, but not as much time as doing it twice 2 nights in a row. Prepping meat etc as I unpack shopping, to then use later in the week or even freeze (I tend to shop once and need to freeze some meat for the latter end of the week anyway).
Mash that you expect to freeze, try and use less liquid when making it (after the boiling and draining part - when adding butter, milk etc back in - someone gave me a tip years ago of using powdered milk not liquid milk as it will retain plenty of water on defrosting).