Sort of all of the above? First, I check the long-term weather forecast online. (No, really. It's the very first thing I do.) Depending on the 10-day forecast, I scribble a framework on paper - really hot days get the cooler/easy prep dishes. Cold days get more hearty fare. Rainy days get the comfort-type dishes. Then I look at who's likely to be around, whether any holidays/family celebrations/events are scheduled. I look at the freezer/pantry for base items & fill in the framework based on how I feel - a particular meat one day, a new technique the next, meat-free or fasting the next. I have an idea of the sales in the stores, as well as what's coming in season at the farms, so I fill in side dishes or more elaborate main courses around that. Then I'll browse the internet for ideas for, say, ground beef or whatever...if nothing sounds really interesting, I'll go with "tried & true". Often I'll zip around to threads about dinner ideas, or other folks' published meal plans, for ideas. (And thank you to everyone who posts these! I know it takes commitment to keep up with it so the rubberneckers like me can follow along!!) A few years ago I tried subscriptions at a few different meal planning sites (now & then a good Groupon will appear for those, or coupon codes like Dave Ramsey's), and I have those menu/grocery lists on a thumb drive for reference, too.
For me, there are 2 really sucky parts about detailed meal plans, as essential as I think they are: a) schedules ALWAYS change, so I'm always moving the meals around...which is just a drag, and b) sitting my butt down to finalize a plan, knowing that it's going to change (see previous).
I'm a big believer in The Plan, though, even if I have to make myself do it at gunpoint. It really does save money, and it makes kitchen/meal prep time more straightforward. I hate the "stand in front of the pantry shelves, staring blankly" moments even more than I hate sitting my butt in the Meal Planning Thinking Chair. I even bought one of those "Martha Stewart" removable weekly stickers for the fridge - Staples carries them in their "Martha Stewart" display. It's a removable/restickable white-board for one week at a time. I put magnets on the caps of dry erase markers so they'll hang beside the sticker. And I stuck the sucker right at the level of the (upper) freezer door handle so people *have* to see it. No more "MOM, what's for dinner?!" I also bought a couple of the square dry-erase plain white stickers to go over it, where I keep a couple lists for people - one is a list of quick/snack items available & where to find them (eg "Pizza crusts - chest freezer" and "Cookies - basket"), a shopping list (no excuse not to write what you just used the last of...a pet peeve!), a checklist for whoever is feeding the dog so he's not double fed (and he'll convince you he's starving if he thinks you'll fall for it!), and a list of what I've got going - yogurt chilling for cream cheese, things thawing, leftovers, etc. It really helps me keep track of what's going on, foodwise.
I have a reference list of meal planning sites somewhere - I'll try to dig that out this weekend in case anyone wants it. I found a lot of useful (free) info.
I do subscribe to a few magazines - got the subscriptions a few years ago on some "renew for $2/yr" type specials. I keep them around, and when I'm really bored (that 15 minutes once a month...) I'll browse them for ideas. I love them, I just don't have time to really delve. If it's not quick, straightforward & easy, these days I'm not interested. When the preschooler is a little older, I'm sure I'll enjoy them then!