Need custom fields with cart variants that are reusable on many products

[t68]

Hi!
I´m working with a web shop for accessories (necklaces and bracelets) and I can not figure out how to set up custom fields for my products. I have tried myself and I have searched these forums but haven´t found or understood how to do it. Here´s what I´m after:

On one piece of jewelry I would like to list of variants of the type of necklace that can be ordered togehter with that thing. Each type of bracelet has a different price that should be added to the product price .
I managed to do this using the custom field for cart variant. But If I use that method  (the way it works for me anyway) I have to add these manually for each and every product that should have these choices of necklaces, even though the varants, info and prices are exactly the same.

Isn´t there any way to save a set of cart variants so it can be reused on other products?

Thank's for any help solving this. The answer i probably embarrassingly easy. But hey, I´m a guy and we're lousy att searching and finding stuff :-).