Soft works but for my tastes, 3D geometrics do it. When the icons slide over, its like you can see some levels deep. I never used this with android so if I were you, I wouldn't use them.I think soft natural images look best behind the tiles. Computer generated art reminds me too much of Android.
I tried a pic of open sea water...I did like this.
Have to say I am a fan of hard edged techy type backgrounds.
Some of the backgrounds do tend to overwhelm the screen.
I may just start going minimalist so I can enjoy the homescreen backgrounds and maybe even freak peeple out if they ask where I got that launcher.