I used soapcalc.net for all of my calculations until I purchased the soapmaker program. When I first started making up my own recipes I used the oils I had on hand (olive, coconut, lard and castor) I wanted olive to be at least 40% because of its qualities, I read that castor over 5% could make a bar soft and coconut over 25% could dry out skin so I stayed under those percentages. Basically, I adjusted my percentages so that my final recipe would be about in the middle of each range (hardness, cleansing, etc) to start and then did some tweaking to get the conditioning number into the higher range. You need to remember that the numbers are just guidelines. If you plug in 100% olive oil, the numbers look awful, but it's a great bar of soap. The same thing goes for superfatting. 5-8% is a good range for most people.
