If you have a special event coming up like a wedding, a shower, anniversary party or whatever and want eco, guest and pocketbook friendly favors these are great for all three.
Here's the soap bar favors I made for our wedding, there were none left over, everyone loved this as a favor! I was warned whatever we made there would be tons left over, but not so with these bars.
Here's a picture of the soap bars. These bars were around 2-3oz each and cost me around 50¢ a bar to make. I make my soap from scratch and if you want to go that route you can find all sorts of great info for making homemade soap online, http://www.millersoap.com/ is one of my favorites. If you don't want to try making it from scratch you can do a melt and pour with a glycerin base which is super easy. If you live near a Michaels they normally do 40% or 50% off coupons in the sunday paper and you can use this to buy their 10lb tubs of glycerin melt and pour to make it around as cost effective to make the same amount as making from scratch. (although you won't get the homemade quality, but they are still nice for favors!)