One thing we have done is to use large plastic tubs with locking lids (not actual locks just comes over the top) for all our clothes and gear. It's much more practical than suitcases for camping and waterproof in case of leaks.
This year though I plan on trying a different approach for clothes. I'm going to get the plastic storage "drawers" from
walmart. That way we can seperate the clothes into drawers to make things easier to find. I figure 2 of the 5 drawer "towers" from Walmart will store the same amount as one of the big storage tubs in about the same space.
Either way you end up with a nice compact, leak resistant, and durable storage medium for tenting. It also packs well in the bed of a truck. Here is an example of how it looks after I get it packed up each year; I like to put a tarp and net over it for additional protection on the way down: (that look on his face is the packing up to go home look

Gotta say I always feel the same way)