Dynamat

Also make sure that after you remove the lid, you look for anything like boards or heat sinks that come within a few millimeters from the lid. Avoid applying in those areas where the Dynamat would make contact with something once the lid is reinstalled. I had to avoid several areas.

I was told to use one inch wide strips. After cutting to the correct sizes, when you apply the Dynamat, be very careful when pushing down/rubbing the edges that you just cut. The metal layer is extremely sharp and can cut your finger easily. No matter how careful I am, I always end up with a few cuts. They make a roller for that, which would work for a lid.