For 1 lb batches, I use an 8x8 silicone pan I picked up for $9.99 at Bed, Bath and Beyond. It works great for the small batches and the soap comes right out with no muss or fuss...
I also work in grams when I am making 1 lb batches (454 grams=1 lb). I find that 1 lb is easier to test stuff...