As anchors, I use patchouli, litsea, cedarwood, and sometimes even vanilla. Someone once said that perhaps adding some castor oil to the batch also helps retain scent, maybe because it is quite thick, rich and viscous. I'm not sure, but I always add some castor to my CP soaps, and they retain their scents very well. I also store them in plastic boxes with lids after a 4 week cure.