This is the most simple, straightforward recipe you can get.
It takes just 3 ingredients – Citric Acid, Bicarbonate of Soda and Fragrance Oil.
Included in the kit will be 3 moulds to start you off.
The kit is 600g Bicarbonate of Soda – 300g Citric Acid and 30ml Fragrance – you choose which fragrance you would like from any fragrance oil on this site and add that at checkout in the comments.
This kit should give you plenty of bath bombs to try. The moulds that come in 2 halves are a little tricky to get used to so you can also use any other mould that is in tray form, exactly as would be used for soaps and melts.