My Vampire Counts are the first army I have fully magnetised. As a result, I can transport my entire army, already set up and on their movement trays, in a series of containers. I use plastic containers designed for under-the-bed storage, with a non-slip plastic matting that I cut to size and lay in the bottom, and I find this to be more than enough to prevent the trays sliding around during transport. Other people use trays with metal inside them so that the magnets grip on, but I don't find this necessary for day-to-day transport.
Beautifully, these plastic containers double as day-to-day storage, keeping my miniatures safe and dust free. And to cap it all off, it's cheap as chips! No more spending hundreds of dollars on miniature cases, and then having to spend twenty minutes at the start of each game pulling them out of their foam and setting them up!