This tutorial is to give aesthetic advice for your home or building.
Basic things
Floor
I recommend that it shouldn't be grass, that looks bad. It is better to put a wood (beware fire), brick, or stone floor. Smooth stone slabs look good as tiles. Wool is decorative, but again, keep it away from fire hazards. Carpet is a much better alternative to wool, as it is not flammable.
Windows
Do not use glass blocks, as you're missing an opportunity to save materials. Use glass panes. If windows are at two blocks above the ground, it is easy to see out them.
Roof
If your roof is 2 blocks high, it's not good because people can't jump. Break the roof and adjust it so that it measures at least 3 blocks high. On the other hand, Endermen will be able to teleport in your house if it's 3 blocks or higher. A half slab ceiling will fix both.
Stairs
If you have staircases that require jumping instead of stair blocks, you better change them. It is much easier to walk. If you want long stairs, use slabs.
Hall
Make a hallway if you have multiple rooms. They should be three or four blocks wide. Use carpets for this part. Recommended also leave a space for a window, so will look brighter.
Exterior
Include a garden of shrubs, flowers, a few trees, and some potted plants.
Rooms (for houses)
Kitchen
Include table(s), a sink, a furnace, a crafting table, and chests to hold food.
Living Room
Include chairs and couches, and something decorative or something to do.
Bedroom(s)
Include a bed (duh), paintings, a jukebox, and a dresser made by stacking chests.
Bathroom
Toilet, sink, shower, bathtub. Ideas for these are in some designs.
Some Designs
These are some realistic designs.
Furniture
Chair
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Note that you can make a couch by adding more stairs.
Table
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A village-style table can be made from a pressure plate atop a fence post. As of 1.6, carpets can be used the same way, and often look better. Connecting more than one table when using carpets will look better also.
Appliances
Sink
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Large Building Decorations
Fountain
Side View
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Top View
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