For everyday use around the house I have a very minimal protection case (Incipio Feather).
However, for traveling I use a CaseLogic TNEO-108 weather resistant zippered neoprene case. Putting a Mini that's already in a case into another case is a bit redundant, but I'm cautious.
I got mine on sale at Fry's for $14.99; have recently seen them at Target for $17.99.
Some info
here
Marty