I do a similar thing as mentioned above, which is cooking ground meat and freezing it in approx. 10 oz portions, so tacos or spaghetti sauce are that much faster to make.
For the summer I took to sous vide cooking chicken breasts, simply seasoned, and freezing them in their bags. The sous vide circulator set at its lowest thaws meat pretty quickly, or I'd get it out in the fridge well enough in advance to thaw for dinner, and finally finish it on the grill. So this is a lot better quality than any pre-cooked chicken I've bought, but pretty much the same convenience.
For meal planning, I have a spreadsheet with our ~12 or so repeating meals, as well as some 'emergency' meals, listed down rows. Across columns I have the date for each week, going back about a month, so I can see how much each meal's being used, and if it's time for a break or to bring something back into the rotation. So I start meal planning for the next week on Thursday, just placing x's for each of the meals for the week, and then I plan groceries around that. On Sunday I assign the day for each meal based on our schedule for the week (based on planned disruptions in evenings, and work/school schedules).
I also have the "lead time" for each meal, so I can sort of line that up with days I work from home, vs days where I'll be getting home at 5:30 and dinner has to be on the table at 6.
The worst emergency meal is where I throw a cup of dry rice, 2 cups water, and a couple frozen chicken breasts in the instant pot and let it go 15 minutes, and microwave frozen veg in the meantime. Could be worse, for sure, but it improves if you chop the chicken up and mix it together with some soy sauce or open pit bbq sauce.