The basics of safely storing flammable substances are simple: keep them separated from the rest of the shop, and as far away from possible sources of ignition as possible. Most of all, keep them isolated, and away from the rest of the workshop.
In spill management, containment is absolutely vital. A spill within a manageable area is one thing to clear up; it can be done quickly, targeted specifically by your Ecospill spill kit. It is when the substance reaches open areas, exiting in to watersheds or soaking in to topsoil, that cleanup suddenly becomes more onerous and complex.