Tips on packaging bulbs for shipping?

[Desirai]

I am going to trade some of my canna lily with a friend. She's going to send me some red and orange and I'm sending her some of my yellow and white.

However I don't really know how to package them.

I watched some how to videos on youtube on how to get them apart and out of the ground. But..

When do I dig them up?
Do I ship them dry? Do I wrap them in moist paper towels?
Should I wait til they are dormant (in about December) or dig them up now while they're still flourishing/blooming?

Tips please?