when you first need to build near the black forest and later biomes, dig a dry moat around your base that has steep edges, you can totally troll/mob proof any base and all you have to do to get back in is run and jump. I normally build beside the sea anyway so you can dig it down so that it's actually a wet moat. Build enough basic workbenches inside the moat so that the circles cover all ground, then nothing can spawn inside your base. Never have to rebuild anything even when you get the larger base sieging events.

you can also easily farm trolls with a basic bow as they can get to you.