My wife typically takes 5 or 6 on our 10-12 day trips. Ha
She keeps them in individual plastic bags and she transport them inside of shorter cardboard boxes, usually 2 or 3 in each box with tissue paper inside. (Box tape to keep them closed. Ha)
The boxes fit on one side of her checked suitcase. She stacks her shorts and t-shirts on top of them and then zips up the cover on that side.
She usually brings a pair on the plane that she carries on as well.
At the house she just keeps the ears in the plastic bags and keeps them in the cardboard boxes, taped up and stacked in the closet.
Her ear game is serious business! LOL