Step 1: Save that cork
Step 2: Cut cork into discs
1. Cut all the way through and create lots of little discs, or
2. Cut almost all the way through and leave the discs attached to one another, or
3. Create a combo of 1 and 2.
I like option 2 because I can tear off the thickness that I need.
Tip: Rolling the cork a little as you saw through helps.