My main base has the wooden walls and spikes around it and, like you said, I just run outside the walls to meet any invasion. I’ve overlapped crafting table radii inside the walls so that monsters won’t spawn there and that system has worked fairly well so far.

For other bases in more hostile places, like the plains biome, I get cheesy and dig a deep moat with stone walls inside the moat. Keeps me from being attacked by spear-wielding fulings and they can’t melee the walls down either.