I use these ones, but the full set hasn't been released yet:
http://www.amiga.org/forums/showpost.php?p=580318&postcount=1They're all using a special fixed 16 colour palette which is OCS compatible (it's the perfect Workbench palette) and don't require 3.5/3.9 or NewIcons to be installed. They are based on GlowIcons and Ken's Icons, except their size and colour palette are consistent.
I think Rebel wants to open-source the icons so other people can add to the set, but there's not really anywhere to do that. I think it's a good choice to stick with them though, because there are going to be several applications and games with graphics sets that use the same palette.
If you want to use GlowIcons you will have to purchase the two CDs that they're on. You can find several random, free ones on Aminet or extract them from ClassicWB. Unfortunately they all have their own palettes and are usually a few pixels difference in size so they don't clean up as nicely.
If you want something really small and efficient, there's this other icon set that Rebel and I are working on, they're all small 4-colour icons that work with any palette and load really fast since they're even smaller than the default Workbench icons, but once again we haven't finished it yet and need help:
http://www.amiga.org/gallery/images/5087/2_TinyWorkbench.pngNewIcons look alright I guess, but they're just a little outdated. It's still handy to have the program installed though, even if you don't use the icons, since many programs and games you download will have NewIcons icons with them.
Sorry I can't recommend any easy option.
