Make lye water. Using a digital scale, measure out the lye and water in separate glass containers. Combine them by adding the lye to the water. (Remember: snow floats on the lake.). Stir until the lye dissolves. The temperature will shoot up. Place this in a safe place to cool.
Melt oils. While the lye solution is cooling, measure out the oils butter and combine them in a large stainless pot. Melt them over low heat and heat them up to 130-140 degrees. Set them aside to cool.
Check temperatures. After 2 hours, check the temperature of both solutions. They should be around 110 degrees. (A range of 100-120 is fine.). If not, allow them to cool longer.
Prep mold and mix-ins. Prepare your mold and measure out any fragrance or color you will be adding. (For the best blending of colors, mix some color into a few drops of melted oils.
Stick blend to trace. Pour the water and lye solution into the pot with the melted oils. Blend with a stick blender until a thin trace is reached. The soap batter will noticeably thicken and a trail of soap will sit on top of the liquid rather than immediately sinking in. (This will take about 1 minute.). Add the color and fragrance and stir by hand.
Pour into mold. Immediately pour the soap batter into the mold. Smooth out the top with a spoon or spatula. Allow to cure at room temperature, uncovered for 24 hours.
Unmold and cut. After 24 hours of curing, unmold and cut into bars. Allow to cure at least 3 weeks in a well-ventilated place.
I don't recommend getting fancy with your first soap recipe. A fragrance and maybe a simple color is okay. But no crazy designs, and don't expect perfection.