Sensory deprivation tanks might be interesting. I feel like they are falling out of fashion though.

Definitely insurance. Heaven forbid you accidentally ruin something priceless you were not supposed to touch.

I have heard that an LLC might not mean much because the difference between you harming a client or your LLC harming them are pretty minimal if you are not hiring anyone or have no contractors. I am not a lawyer, but I would be interested to know how true it is.