Measure the existing access hole. Cut a piece of AA plywood in any thickness that is 2 inches larger in each direction for surface-mount access covers or the exact same size and thickness for flush-mount covers.
Create your own stencils by drawing a shape on a mat board. Make all narrow portions of the design wider than the width of the blade to prevent binding when you cut the plywood later.
Use a mat knife to score the mat board about one-third of its thickness along the pencil lines. Score along the lines on the board again, one-third deeper. Repeat one last time to cut all the way through.
Sketch a pleasing arrangement of shapes on the most attractive or highest-quality side of the plywood using ready-made stencils or the ones you created yourself. Use gentle, light strokes of the pencil to make the marks easier to remove later.
Don a dust mask, wraparound eye protection and ear protection.
Select a bit with a slightly larger diameter than the width of the jigsaw blade. Drill a starter hole in a large central portion of one of the shapes drawn on the plywood.
Insert the jigsaw blade into the starter hole, and cut from there to just outside the pencil lines to create the cutout shape. Use relief cuts from the starter hole to various points along the pencil lines to prevent binding the blade on tight curves.
Pull hair longer than chin-length into a bun, not a ponytail, to prevent getting it caught in the collet -- which is the working end of the hand-held, high-speed rotary tool -- during use.
Smooth all rough edges of each shape using sanding drums on a high-speed, hand-held rotary tool in larger areas with gentle curves. Smooth tight areas using jeweler's files.
Stain one side of the access panel if desired, and allow it to dry overnight. Turn it over, stain the other side, and allow it another 12 hours to dry. Give each side a second and third coat if desired, allowing each side to dry completely between coats.
Position the decorative wooden access panel over the access hole. Using a smaller bit than the diameter of any wood screws or the same-sized bit for bolts, drill pilot holes where needed. Use existing holes from the original access cover to decide where to drill.
Use the fasteners from the old access panel to attach the decorative panel if they were not stripped or bent during removal. Use matching new fasteners to replace any defective ones.
Use regular or scrapbook scissors to cut a variety of pictures from magazines, old postcards and greeting cards or gift wrap. Cut as many multiples of the same picture as you can find. Sort the pictures by theme, such as Christmas, Valentine's Day, Thanksgiving, the four seasons, southwest/Native American, sports or other hobbies.
Cut a piece of class A or B plywood 2 inches larger in each direction than the access hole. Cut a piece of poster board to the same dimensions.
Arrange your chosen pictures on the poster board. Use single copies of one or two of the multiple-copy pictures you found as focal points in your arrangement. Keep the additional copies in separate piles beside the poster board.
Lay the plywood access panel on a drop cloth, and brush the entire surface of the lowest-grade side with a coat of clear acrylic wood sealant. Apply a coat of that same sealant to the bad side of a picture from the center of the arrangement you created on the poster board, and press it in that same position on the plywood.
Continue applying clear acrylic wood sealant to each picture from the arrangement on the poster board and pressing it in that same position on the plywood access panel. Allow the arrangement on the plywood to dry for at least two hours.
Apply a coat of sealant to the entire arrangement and any exposed areas on that same side of the plywood access panel. Allow the panel to dry overnight. Feather the edges of each picture using gentle strokes with extra-fine sandpaper, working from just inside the edge of each picture to just past the edge.
Repeat Steps 5 and 6, and apply two more coats of sealant over the entire arrangement, allowing the sealant to dry between coats.
Hold the bad side of one of the multiple-copy pictures against a pair of scissors while pulling downward, causing it to curl. Apply clear adhesive to the good side of the picture, and allow it to dry for two hours. Apply clear adhesive to the bad side, and press it into place on top of the matching picture in the arrangement.
Repeat Step 8 at least twice to create a three-dimensional picture on the access panel. Apply a final coat of sealant to the entire arrangement.