Drywall:
The hole is carved around the edges to remove any rough burrs then a plug is set and non-shrinking spackle applied with a tape knife.
After the patch has cured and you have primed and painted the area there will be no visible clue the wall has been drilled. Finally the areas worked on are vacuumed, swept or washed down. It is recommended that insulation of interior or exterior walls be completed before you paint your home.
The Attic Insulation Process using fiberglass batts:
This is only recommended if you plan on doing future work in the attic as batts hold up better to people crawling over them.
Fiberglass batts are laid out as tightly together as possible covering the entire attic, except heat sources. While not creating a seamless blanket of insulation, as with blown in cellulose, it is the next best way to insulate an attic.