You can make fabric panels from light to heavyweight fabrics in solids or prints. If you use lightweight fabric, choose one opaque enough to hide the door finish. For example, a lightweight cotton floral with a white background might work just fine on a white, painted door, but not on a door with a dark stain.
If you opt for a printed fabric, choose one with a repeat no larger than the smallest door panel. The repeat is the size of the fabric pattern before it repeats itself in both directions.
Before you start cutting, measure the length and width of each door panel. Subtract a quarter inch from the length and the width of each, and cut fabric to those measurements. Cutting the fabric slightly smaller than the door panels keeps loose threads from showing once you trim the edges. For patterned fabric, make sure the center of the pattern is centered on each cut of fabric.
You can attach fabric door panels with spray adhesive, liquid starch or staples. The right choice depends on the fabric weight and door type. Spray adhesive works on hollow core, metal and solid wood doors, but it can discolor lightweight fabrics. Choose a spray adhesive appropriate for fabric and your door material, and follow the manufacturer's instructions.
For hollow core and solid wood doors, you can use liquid starch to attach the fabric. Starch has the advantage of being reversible, but it works best with light- to medium-weight fabric. To use this method, apply liquid starch to the panels with a paint roller. Center the fabric on the door panels, and then roll another layer of starch over the fabric.
You can staple fabric of any weight to the panels of solid wood doors. Staple around the perimeter of the fabric, about an eighth of an inch from the edge. For a padded, upholstered look, cut a piece of quilt batting the same size as each fabric panel. Staple the batting to the door first, and then staple the fabric over the batting.
Trim your fabric door panels with nailhead trim, ribbon or gimp to hide the raw edges of the fabric -- and to give the panels a finished look. Use glue-on nailhead strips for any type of door, or nail-in strips or individual tacks for solid wood doors. Ribbon and gimp works for trimming any type of door. Glue it around the perimeter of each panel, and miter the corners where the ends abut.