Weigh out the mango butter, cocoa butter, and almond oil in a double boiler or double boiler insert.
Heat over medium heat until the butters have melted.
Add in the arrowroot starch, and mix together thoroughly until it is well incorporated into your mixture. Pour the mixture into a stainless steel bowl that will fit into your freezer.
Place the mixture into the freezer or into an ice bath to cool the mixture as quickly as possible. This will help prevent a grainy texture in the final product.
After a few minutes have passed, remove the mixture from the freezer and use a spatula to wipe the solidified butters off the sides of the pan. Beat everything together.
If the mixture is relatively cool, add in heat-sensitive ingredients like vitamin E and essential oils. Whip them together with the rest of the ingredients, and place the mixture back in the freezer again for a few more minutes.
Remove the mixture from the freezer again and, once again, use a spatula to remove the solidified butter from the sides of the bowl. Use the beater to whip everything together.
Continue the cycle of freezing and whipping until the mixture has solidified enough to keep its shape.
Method 2
Weigh out the cocoa butter and almond oil in a double boiler or double boiler insert.
Heat over medium heat until the cocoa butter has melted. Then, remove from the heat source.
When the mixture has mostly cooled, add the mango or shea butter, the arrowroot starch, the vitamin E, and the essential oils. Whip until fluffy.
If it's too soft to hold its shape yet, place in the freezer or over an ice bath to quickly cool it. (Rapid cooling of melted mango or shea butters is important to prevent graininess.)
Remove from the cold source and whip one last time.
Storage
Spoon or pipe the finished body butter into a storage container. Store out of the heat so that it doesn't melt.
Video
Notes
For easiest weighing of the ingredients, add them one by one to the recipient, taring the scale between each addition to get the scale back to zero.I have provided 2 different methods for incorporating the mango or shea butter. Mango or shea butter can take on a grainy texture if they are melted and allowed to cool slowly. To prevent graininess, either melt it and cool it very quickly or incorporate it without melting it. Choose whichever method you find easiest for you.
Choosing essential oils
Different essential oils can give a different fragrance and feel to your finished body butter. Lavender, for example, has more of a calming effect while citrus oils can be more invigorating. Keep in mind that many citrus oils (especially pressed oils) can cause photosensitivity, meaning that you may be more prone to burning if you wear them out in the sun. Avoid phototoxic oils if you plan on wearing your body butter outside during the day. (Most distilled oils are OK to use, but even distilled grapefruit oil may cause some photosensitivity.)