Homes in general are too limited in interaction. Crafting and damage testing is nice, but it doesn't exactly give the "home is where the heart is" feeling. People have been suggesting storage containers from the start, which I think would help, but even simpler would be things to write on.

Signs -- Could come in a variety of decorative styles and when looked at display a short message written by the owner or those with furnisher access.
Boards -- Like the boards in Hew's Bane, could contain one (or maybe several) long messages posted by the owner or friends/guild members/etc.
Notes -- Sheets of paper meant to be left in another player's home that give a medium-length message.

I'm not dead-set on this exact breakdown or function, but the basic idea is it would really spice up the homestead experience if we could have that level of personalization.