Measure the height of the area into which the supporting column needs to fit. Cut the 4-by-4 to that length with a miter saw. Cut two pieces of 1-by-4 and two pieces of 1-by-6 hardwood lumber in your choice of grains to that same length on the miter saw. Cut eight pieces of 4-inch baseboard molding 6 ½ inches long with 45-degree miters at both ends, one right and one left, with the baseboard standing on edge. Set your table saw fence to 5 inches and adjust the blade height to 1½ inches. Cut each piece of 1-by-6 using this set up to a width of 5 inches.
Glue and nail the 1-by-4 pieces to opposite faces of the post with their long edges flush with the faces of the post. Glue and nail the 1-by-6 pieces to the two remaining faces, with their long edges flush with the faces of the 1-by-4s. Use two rows of nails down each board, spacing them every 8 to 10 inches, with a pin nail gun and 1½-inch nails.
Wrap four pieces of baseboard molding around each end of the column so that the decorative, or top edge, is toward the center of the column. Match up the 45-degree miters at each corner to form a frame around the post and nail them into the hardwood, with four nails in each piece.
Fill the nail holes and seams along the long edges of the hardwood with solvent based wood filler. Allow this filler to harden and sand the column smooth with 150 grit sandpaper.
Apply two coats of stain and clear finish all-in-one to the column with a medium width, fine bristle brush. Wait the label-recommended drying time before applying the second coat for best results and allow the column to dry completely before installing.