You can download 85mb of SFX samples/sweeps from our website for free:

SFX Collection 01

Just click the "free samples" button to the right of the product's 3d image (next to cue in player).

You can get some great sounds by use of layering.

Try layering weird ambiences, reverb tails from bizarre sources, granular soundscapes etc. You can then use automation to shape the sounds with filters, multi-fx etc whilst programming in subtle changes in movement for evolving sounds. Try layering the results with a simple white/pink noise sweep whilst applying different effects to each stem. This is how some of the more creative sounds were produced in SFX Collection with great results!

Using something like an Eventide Harmonizer can help make some very ethereal sounding pads and sfx as well. Its all about automation, effects, creativity and layering.