Like with any other genre, listen to the artists you like and ask yourself what it is you like about their music. And try to recreate that.
I'm listening to A LOT of Éliane Radigue lately and currently exploring her sound with my BARP 2500 build. The Modamp module does pure magic to drones if fed a couple of sines and connected as intended (outputs back to the VCOs). Feed that to a chorus and you can listen to that for hours...