for starters, if you've any pillows blankets etc. in the drum put 'em back on the bed, it could be chilly tonight. tune the batter, then tune the resonant head to a slightly higher pitch. This will bounce the waves back to the batter and lenghtens the decay. Let your beater bounce off the batter head instead of burying it. Also try moving your mic back to let in more room sound. For a really HUGE sounding kick make a tunnel with carpet, moving blankets etc. and try putting the mic at different spots in the tunnel.
When processing try cutting about 8-10 db at 300-500hz and add a touch of reverb and squash the h*** out of it, maybe as much as 20:1. Experiment. trust your ears, have fun.