A round tin with six or seven small pots inside, sold as a masala dabba. It is the correct answer to a problem that individual jars solve badly: a dozen separate containers rattling around a box, each needing to be found, opened and put back.
This matters more than it sounds. The spice kit is the argument that herbs, spices, acid and fat are what separate a good dinner from shelf-stable ballast. That argument only holds if the spices are to hand while you are cooking. A tin you open once and leave beside the pan gets used; six jars in the bottom of a crate do not.
Practical points: get one with a tight outer lid rather than a friction one if it is going in a vehicle, and keep it out of the light. Ground spices lose their volatile oils to light and air faster than whole ones, which is the real reason old spices taste of nothing.
Decant from the supermarket packaging rather than storing the packets. The packets are neither airtight nor stackable, and once opened they are neither.