Protect the insulation from the weather (such as water, ice and water vapors).

When opening the package of insulation allow room for it to expand.

Use both a mask and gloves to protect you from the insulation.

Cut the fiberglass insulation with a utility knife using a straight edge (such as a board) against a hard surface you don't mind being scratched by the knife. Use care when handling the knife.

Make the insulation about 1" or 2.5 cm wider for every 8" or 20 cm of area you are filling. For insulating 16" or 40 cm walls cut the insulation to be roughly 18" or 45 cm wide. The additional 2" or 5 cm will cause pressure to hold the insulation in place until the wall is built. Packing the insulation so it is tight together and hard will loose it's effectiveness.

When you are required to use more then 1 piece of insulation to do a section stagger the insulation in the sections beside it so that it isn't one straight line across a wall where the pieces come together. Cause where the pieces come together to be at different heights. Then you won't feel a draft in the wall when the work is complete and the weather turns cold.