Making Riffs!!

all my riffs and songs come ot me between 11:00pm and 2:00am just from hearing one note, and creating a lick around that note, and making a bar chord progression or sumthing to play with my riff. I play a lot in Drop D and standard tuning, are there other, different tunings that can widen my "riffing" (i hope thats not a real word) abilities? i only know like two scales and a few different chord variations, i dont know any theory, just basics.