Placing insulation in the attic floor is usually easy, requiring only laying the material between the parallel joists of the frame. Walk only on the joists so that you won't fall through the drywall ceiling. You may need to place walking boards across the tops of the joists to make the job easier.  Keep yourself safe with good lighting and teamwork.  A simple slip could at the least put your foot through the drywall of the ceiling below.

Seal up air leaks between your living space and the attic before adding insulation in your attic. In attics, thermal bridging can be reduced by adding sufficient loose-fill insulation thickness, or cross-installed batts, to cover the wood or metal frame as much as possible. In some houses with low-pitch roofs, it is difficult to gain access to all of the attic floor, so blowing equipment may be needed to place insulation in relatively inaccessible areas. In most attics, it is easier to get complete coverage with blown-in insulation. This is messy work and requires expensive equipment.  It is best to hire an insulation contractor for this type of job.

In existing buildings, installing insulation in the cavity of exterior walls is almost impossible for the average homeowner. It usually requires the services of a contractor who has special equipment for blowing loose-fill insulation into the cavity through small holes cut through the sidewall, which later are closed. It is sometimes feasible to install rigid insulation on the outdoor side of masonry sidewalls such as concrete block or poured concrete. When new siding is to be installed, always consider adding thermal insulation under it. Generally the services of a qualified contractor are needed to make such installations.

Here are a few tips to help you prepare to tackle your insulation project:

• Wear clothing adequate to protect against skin contact and irritation. A long-sleeved shirt with collar and cuffs buttoned, gloves, hat, glasses, and disposable dust respirator are advisable in all do-it-yourself insulation projects. Also, read the label and follow all the manufacturer's directions. 
• Do not cover or hand-pack insulation around bare stovepipes, electrical fixtures, motors, or any heat-producing equipment such as recessed lighting fixtures. Electrical fire-safety codes prohibit the installation of thermal insulation within three inches of a recessed fixture enclosure, wiring compartment, or ballast, or above the fixture so that it will trap heat and prevent free circulation of air, unless the fixture is identified by label as suitable for insulation to be in direct contact with the fixture. THIS IS FOR FIRE SAFETY. 
• Older homes should have an electrician’s inspection to see if the electrical insulation on your wiring is degraded or if the wires are overloaded. In either of these two situations, it may be hazardous to add thermal insulation within a closed cavity around the wires because that could cause the wires to overheat. 
• Do not cover attic vents with insulation. Proper ventilation, especially in attics, must be maintained to avoid overheating in summer and moisture build-up all year long.