Crown moldings decorate the stark angle where the ceiling meets the wall. Available in a wide variety of sizes and styles, crown moldings attach to both the wall and ceiling, adding architectural interest. An elegant touch, they can soften and enliven an otherwise boxy room.

Typical costs:
• Standard crown molding professionally installed costs around$8-$12 a foot or about $300-$500per 10×10-foot room, according to U.S. News & World Report.
• Elaborate designs, heavy or exotic woods, the need to stain or paint the moldings, uneven walls and ceilings, irregular layouts with lots of corners, and the use of multiple moldings to create a dramatic effect can bump the cost of materials and labor up to $25-$35 a foot, or $1,000-$1,400for a 10×10-foot room.
• Materials for a do-it-yourself project in a 10×10-foot room range from 90 cents-$3 a foot for wood composite, red oak or poplar, or $40-$120 for a 10×10 room, or $1.50-$6.50 a foot for woods such as mahogany, cherry or walnut, or $60-$260 for a simple 10×10-foot space. Buy about 10 percent more molding than needed, to allow for wastage.
• Correctly making complex cuts at the corners is crucial, and requires owning or renting a compound miter saw, CompoundMiter.com sells kits with instructions, tools, charts, templates and more for $75-$118.
• Precut corner pieces add an additional dash of style and make do-it-yourself crown molding projects a lot easier. They sell for about $8-$20 or more each, depending on size, style and type of material.