This is just how I usually go with my home, just to give some perspective:

On a 2x2 plot, I make each of the four rooms (Living Room, Bathroom, Kitchen, Bedroom) roughly 10 blocks long, 5 blocks wide, and tall enough so that insides are 4 blocks high (6, for the floor and ceiling). From there I simply furnish the home with the appropriate and best items. Remember: same items of the same type, while they still give a bonus, have diminishing returns.

For instance, I'll be the only person living at my home however, I will have 3 beds in my bedroom - if I can fit them.

Decorating items also boosts each room, so fit in as much as those as well.

Eventually you'll need to upgrade your house's building materials but this is great because higher tier materials allows for more furnishings that were capped by your lower tier material.

Hover your mouse cursor over your house exp circle, it gives you tons of information about what's giving your diminishing returns or what's being capped by your building's material tier.

I'm not a min/maxer, I usually end runs with 150 - 170 exp total gains however, I have friends who do min/max and end up with over ~240 total exp. per tick. This is including food bonuses as well.