A -- There are new insulation materials that are not itchy like standard fiberglass batts you find in most home center stores. These materials are extremely effective and adding them will cut your utility bills year-round. Also, don't necessarily write off professional installation as too costly because the energy savings often pay back the cost in a reasonable period of time.
Before adding more insulation just because you think you need more, check with your local building codes department for the recommended amount for your ceiling, walls, floors, basement, or crawlspace. If you already have enough insulation, adding more will not save a significant amount of additional energy: the small amount of savings will not justify the expense or the consumption of the materials.
Itch-free fiberglass insulation is produced using a more complicated manufacturing procedure than standard insulation. I installed several rolls of it in my own attic and it caused very little itching, if any. It is completely wrapped in a poly-film covering so you hardly touch the fiberglass itself. Although it looks like standard itchy insulation, it feels like fluffy cotton balls when you cut the ends of the rolls to length.
In addition to the itch-free fiberglass insulation material mentioned above, several other types of standard (itchy fibers) insulation are also encapsulated in poly-film wrap. This makes it easy to handle and install without getting itchy. Since you must slice the wrap when you cut it to length, you may have some contact with the itchy fiber, but very little. No matter what type of insulation you are working with, it is wise to wear gloves, long sleeves, pants, and some sort of breathing mask.
When insulating an existing wall or around plumbing and electrical obstructions during construction, it is important to fill it completely with no voids (unfilled areas). Just a small percentage of voids can result in a significant energy loss. Make sure the insulation is also packed tightly. Even though most fiberglass batts have a very light coating of adhesive on the fibers to keep them fluffy, almost any do-it-yourself insulation material will settle somewhat.
Using a professionally installed non-settling type of insulation is often the most effective method in areas with obstructions. One type of non-settling insulation uses blown-in fiberglass fibers mixed with strong adhesives. After it is blown into the wall cavity to fill all the gaps, the adhesive sets up to eliminate settling. When installed in new walls, nylon netting is stapled over the studs and the insulation is blown in behind it.
Another type of effective professionally installed non-settling insulation is low-density polyurethane foam. It has about the highest insulation value per inch thickness of any material, so it is ideal for locations with limited space. Immediately after it is sprayed, its volume expands about 100 times, creating millions of microscopic insulating cells. It fills in effectively around most obstacles inside a wall. When it foams up during installation, the cell structure it creates is closed so it also seals air and moisture leakage spots inside the wall.
When buying insulation, remember you are paying for the R-value insulation level, not just the thickness. Insulation can be fluffed to be thicker, but it still has the same, or lower, R-value. Any insulation contract should specify the final installed R-value of the insulation.

Write for Utility Bills Update No. 448, a buyer's guide to insulation. Include $3.00, a business-size SASE, and Update number. Mail requests and questions to James Dulley, Kentucky Living, P. O. Box 54987, Cincinnati, OH 45254. Go to www.dulley.com to instantly download.