This MakeKit kit includes:
2x Reusable aluminum molds
Baking soda
Coconut or almond oil 
Essential oil (3 fragrances to choose from)
Colouring
Citric acid
Epsom salt
Thickener
Simple instructions with images 
Difficulty: 3/10 
Suitable for: 6+years. Girls, boys, teens and adults - this project is great for everyone!
You can make this in: half an hour (plus setting time)