with pads a lot of the time you want to add delays and LFOs to the sound to add movement and variation or they will come off boring as hell or use them as a sound bed over your vocals drums and main melody in place of maybe a bass line
I like to use sampled material in my pads. I do a lot of location / ambient recordings with a Tascam spot recorder. Then I take these ambient samples, manipulate them in a large variety of ways, blend them together with stuff I've done in a synthesizer, this makes for pretty interesting sounds. Using 1 minute of recorded audio that is constantly shifting in a "real" way helps the pads to sound more organic.
Add layers from other sources. Try strings, brass or organ. Audition a few different choruses, they have a lot of impact on the final width and movement, play with inserts vs sends, slowly and subtly autopan elements against each other. Definitely try to keep things evolving, but not so recognizable. Modulate the reverb or alternate between 2 to give the "air" a moving shape as well.