Choose flannel for the flannel board. Colors like green or blue act as a general outdoor background. Green on the bottom half and blue on the top half of the flannel board will resemble the ground and sky.
Measure the corked area of a cork board, then measure a section of flannel to fit the cork board. Measure again, for accuracy. Mark the measurements with a marker as a guide on where to cut the flannel.
Cut the flannel to fit the cork portion of the board using a sharp pair of scissors. Attempt a straight cut, but don't worry if there are small errors. The edges of the flannel board will be covered with trim.
Glue the flannel to the cork using a hot glue gun. This must be done quickly, or the glue will dry before the flannel adheres to the cork. If this happens, pull it up and try again. After gluing the flannel to the cork, smooth the flannel with fingers so that it is completely flat, without bubbles.
Measure rick-rack trim to fit along the edges of the flannel board. Glue in place with glue gun. Allow the flannel board to dry completely before use. Use flannel shapes or commercial flannel board figures to tell stories using the flannel board.