Unless I'm ungodly busy, I just plan my weak's meals when looking at the circular and considering what I have on hand. I won't generally take the time to actually figure out recipes, most of the time, but it's easy enough to glance at everything on sale and come up with a loose picture. I'm generally fully stocked on spices, so the only thing that matters is whether or not I need fresh herbs or citrus.
As a general rule, I don't spend more than $2 on meat. I don't each much of it, so it all ends up in the freezer anyway. And I don't eat much pork/beef, so that reduces things nicely. When there's a good sale, I buy as much as I can conveniently freeze. Of course, I do increase my costs a tiny amount by buying sandwich bags so I can freeze (trimmed) portions. Still works well, though.
I almost never buy produce that's not on sale unless it's something I really need or am really craving. Red peppers, for instance. I love them, but I won't pay an extra dollar a pound for them. Even worse with yellow/orange.
Only things I'll reliably buy for full price are onions/garlic (if I'm going to run out before the next week) and greens (kale, if nothing else is on sale).
All the rest of my produce is on sale. But I do generally buy sufficient fruit to last me through the week with at least one piece a day, preferably two. That goes to whatever is on sale (hate Bartlett pear weeks. Those bastards are never ripe...)
Fortunately, there are VERY few fruits and vegetables I don't love, and almost none that I can't tolerate. So it's not hard for me to be happy with whatever is on sale, as long as whatever is on sale is decently ripe (as in, I can use it within a week). Broccoli rabe is the only thing that comes to mind that I can't tolerate, and that's because I'm sensitive to whatever makes it bitter. One bite of it, even if it's been properly cooked, and all I can taste for at least an hour afterwards is bitters.