My first time I also added them to soil-less mix and watched as the explosion took place within the hour. It is an amazing sight!
I also did as Rebecca mentioned and dug holes, added reconstituted crystals, mixed in some old coffee grounds and compost. The plants (hostas and ferns) loved it and are still thriving in a very dry spot that doesn't even get rainfall.
Just one coffee scoop of crystals added to a jug of water, wait 30 minutes, and you're ready to use them for your next projects. Easy!