I often get raids. I usually get troll raids when building a new outpost, that is why I focus on defense first before building any building. When I do get attacked, I lure them away from buildings. I use steep cliff walls to protect my buildings...I have raise ground and/or mine to get steep cliff.

For work benches, I put them in the air to keep pesky monsters from attacking them. About 4 meters high 2 wood or 1 core wood beam. Do floor, walls and roof so it is fully in closed. I seen trolls leave alone while taking out my animal fence that I gave up on for now.

For gardens, again raise ground with animal fencing to prevent pesky monsters going in. Also add standing torch post to keep stuff out too. I did without fence and torch post and had grey dwarf destroying my garden. You can use bees to help protect garden too.