Cut 2 pieces of felt the size you want the frame to be. Cut out a smaller square in one of the pieces, so you now have the front and the back of the frame. Glue the plastic to the hollowed out piece of felt and sandwich it between the two felt squares. stitch the two pieces of felt together. Make sure that the plastic is sandwiched between the two and that you leave The top not stitched to each other to be able to put a photograph in. But embroider just the top piece of felt for uniformity...
For the roses I cut two felt pieces in spirals and wound them tight and stitched in three pearl buttons.