Mount your rose on acid free paper or fabric using as little glue as possible.

You'll need the frame with glass, matt is optional but nice, foam board or similar backing, aluminum foil or drafting mylar, and aluminum tape. A small amount of silica gel or other desiccant is desirable but not vital. You may want to use kraft paper to cover the back of the frame for a finished look, again not vital.

Gather these materials and follow the instructions on the page below.

Good luck!

Here is a link that might be useful: Framing a Pressed Rose