Coupon Buy 1 X Get 1 Free Y.
The category for the free gift is applied in the top part of the Buy X Get Y Free configuration under the Actions tab. Below that we are applying all the products SKUs that accept this rule.
To be clear, basically the "Y" items are the top half and the "X" items are the bottom half of the configuration. It isn't necessary clear so let me know if you have any questions.
If you purchase a pendant you receive a free greeting card. Amasty Documentation Jan 2015