For example, they were fighting a robot in a recent session. I was careful to mention that most of its case was off. Loose wires were hanging from its arms, and it had an exposed battery pack. Instead of announcing that they would try to cut the wires with a knife or target the battery with a heat ray they had, or just use their burning torch to melt the wires, they opted for round after round of "I attack again".
I would describe the robot swinging at one of the players on a miss being attributed to one of the wires getting caught on a light fixture nearby, specifically how the robot takes its time disentangling itself instead of simply ripping its arm free. Describe how it even lets one of the players get a solid shot in while it makes sure to gently untangle the wire. You'd be surprised how many players get caught up in the "flavor text is flavor text" mindset. And to be fair, a lot of modules have no tactical hints buried within their descriptions at all. Describing something multiple times in different instances, especially when it interrupts the normal back and forth of dice rolls, can hammer it in. I wouldn't just mention something once and expect them to suddenly connect the dots.
As for teaching them tactical retreats? You fucking got me, man. I actually run in a pretty decent group, and it's next to fucking impossible to convince players to not just charge the nearest goon and sit there full attacking until one side falls over. The concept of abusing monsters who lack ranged options by peppering them with something as simple as slings and kiting them into a chokepoint is like pulling teeth.
It also kills the roleplaying aspect. You wouldn't
want to engage a
dire boar in melee. You'd plug that walnut-brained slab of surly muscle with as many ranged options as possible, and you
certainly wouldn't just engage a pack of them in the open. But the Ranger kitted himself out for two-weapon fighting, and even though he has an insanely high dex score the fucker didn't even pack a longbow, so 9 times out of 10 that faggot's going to charge the nearest boar because next turn he's going to be swinging four times now that he can plant his feet and full attack. Except, he charged, so now his AC is two less for a round, just enough time for all the other boars in the clearing to surround him and turn him into chunky salsa. Oh, and the cleric is
two turns away instead of one because the ranger charged at the very edge of his 30 ft move distance and the cleric's movespeed is 20 because of his armor, so if there's anything left of the Ranger after the first round the cleric's gonna have a hell of a time getting to him and dragging his lifeless body out of there.