The first step to properly insulating an attic is to determine the R-Value recommended for your climate zone. The R-Value indicates the type and amount of material that is necessary to insulate the attic.
The insulation for the attic access should be permanently attached, and it should meet or exceed the R-Value of the rest of the attic.
If you use multiple layers of insulation, install the first layer parallel to the attic framing. The second layer should be set perpendicular to the attic framing. This ensures optimal thermal performance by reducing the possibility of any uncovered spaces.
All layers of insulation should fit snugly between the attic frames.