When my dad and mom went back home to Hawaii (from CA), I packed dad's humi (40ct with 22 cigars and a Boveda pack) with air pillows to allow no movement of the cigars. The cigars were packed in ziplock bags and stacked on each other (about 3 rows, longest cigars on the bottom to shortest on top), where the various sized air pillows (including bubble wraps) took up the slack spaces. I then wrapped the humi with plastic wrap to prevent/reduce dehydration on the plane, and then wrapped a foam-like sheet material (usually you see these wrapped around electronic equipment), and then taped some foam cornerings to the 8 edges of the humi. Dad then put it into his suitcase (hardshell Samsonite). It arrived in Hawaii undamaged, and the cigars maintained a 60-65% humidity.
Sounds like a lot of work, but it helps when my parents carry-on was already loaded with gifts for the rest of my family in Hawaii.