What do you do to make combats feel unique?

I asked my party feedback on the campaign so far (4 months now) and they have been enjoying battles where encounters feel puzzle-y. For example, I had this zombie invasion where a horde of undead was increasingly coming and they had to break a big ogre's bracelets to disperse the enemies. They found this exciting.

I have done, and have planned, many more encounters with gimmicks (traps, enemy mechanics, terrain). The problem I find is taking it into the "daily" aspect of the game. Putting challenges into meaningful battles is doable but, say, they encounter a group of goblins in the forest, or a bewildered owlbear. How do I make these encounters matter? Should I not, to highlight the "mundane" part of the adventure against the real epic battles? Should I omit them completely? The game reminds you to constantly add "random" encounters and traveling challenges but I feel like it doesn't work when planning curated fights. What is your take on it?

For reference, my party is level 3 (almost 4), which I feel like it also plays a part since at level 5 the game upgrades combat-wise, so I plan on not pulling punches so much.