So the soap calc website is the best location when it comes to mixing up your own recipes. When it comes to molds, 3d printed molds being ridged, it could possibly make it hard to remove the post when hardened.

A better suggestion would print out a full bar with the 3d printer in the design you want the bar to be with like 50% infill. Then when finished printing, using a combination of construction epoxy (clear), dish soap and water, you can make a flexible mold to make getting the soap out way easier. You can use this recipe to make a mold of anything, so get creative.

Here is a little instructables link on how to do this.

https://www.instructables.com/id/Worlds-easiest-silicone-mold/

Let me get you the quick run down on soap and whats important. You want a hard bar of soap. Any soap will harden, given enough time, but certain oils like coconut oil and lard tend make a harder bar of soap. Castor oil is what makes the soap really foamy, its great stuff but you don't want to get wild with it. 5% for body bars, 10% for shampoo bars. Sugar will also make the soap have more bubbles, but sugar will also increase the temp of the soap after mixing it all together and if you use too much, it can cause the soap to have a giant crack in the center or even volcano all over the place. Salt added in small amounts will cause the soap to harden and so will 2% bees wax to volume.

Super fat is the amount of fats left over after the lye has performed its chemical reaction with the oil. 5% is good for areas that has hot humid climates, but people in dry cold climates will find 7 and even 10% super fat iis soothing. Experiment, some people will say its greasy, others will love it.

Going with a 100% coconut oil soap will make a very drying soap unless 25% super fat. Its just a really drying oil but at 0% super fat, it makes a GREAT clothes bar and its hard as a rock, make sure to check often after pouring it and cut sooner than later because once hard, its like a brick.

Olive oil is a really nice oil to use that is a semi-soft oil. A full bar of soap made of only olive oil is called a castile soap. This type of soap will take some people 6 months or more for it to cure enough to unmold and will still be soft. It will harden after a long time and makes a super luxurious bar of soap.

Heres a couple pointers. It takes 4-6 weeks for a bar of soap to be fully cured. After 72 hours, most bars of soap with proper ratio of water, oil and lye will have its chemical reaction done and will be ready to use. The drying process makes the bar of soap hard and that means it will last many showers for your customer. Also, promote the customer to use a soap dish that removes water from the bar. Sitting in water will kill natural soap which is good for sales, but people get pissed off soap will desolve away in water. Go figure.

Also, citrus essential oils dont stick in soaps unless you have something for them to bind to. I would recommend french red clay used in conservative amounts to bind these. This type of clay is also great for exfoliation.

Careful storing soaps together, scent can and will mix together with funky results. Making small batches allows you to keep your inventory rotated often but also makes it easier to store. I love Pop-it Containers they work really well.

Veggie racks with slits work well for drying soap something you want to have a nice place with AC. If AC is not possible because of off grid, I personally use a small bin with a container of humidity absorber balls that will draw the moisture out. Its not the easiest way but its my only option.

I only use natural colorants for soaps. Chocolate powder, Carrot baby food, ground up cucumber with peel, aloe with peel, avacado without the peel, turmeric and activated charcoal are all great things to add to give your soaps color and MANY will give your soaps great properties.

Coffee will make a tan soap that has no smell. Using anything vanilla will make your soap brown.

I will try to come up with some other tips and hopefully they will help you out.