I found this technique here. She has lots of great tips in doing this technique.
Use wax, butcher or parchment paper under your tissue paper. Spread gesso over the tissue paper with a brayer and let it dry. Wash the gesso off the brayer immediately.Flip the tissue paper over and spread more gesso over the back side with a brayer. (I think this is to strengthen the paper.) Let dry.
Dilute acrylic paint with acrylic glazing liquid and spread over the gesso on one side with the brayer. Leave some areas uncovered. Let dry.
Repeat with one or more additional colors, letting dry in between layers. I used silver then patina.