Choose a box. A finger puppet stage can fit in a shoe box, but there will be more room for adding a set or props with a larger box, such as a big cereal box or the package from a big toy. The advantage of using a big toy box is that they often have a clear display window, so you do not need to cut one out. If you are cutting out a window for the stage, leave a flap of cardboard two or three inches high to cover the hand that will hold the finger puppets. Then, cut an opening in the flap opposite the stage big enough for a hand to fit through.
Paint the exterior of the box. If the box is made of laminated material, paint will not adhere well, so glue construction paper on the surfaces before painting them. For interesting effects, paint pretend spotlights in the corners or an orchestra pit below the stage. You can also paint pictures of some of the finger puppets that will star in the theater's productions.
Decorate the interior of the box. You can paint a backdrop directly to the inside of the box, or create several backdrops on sheets of drawing paper or construction paper. Stickers, collage art, glitter, sequins, foam shapes and beads can add some three-dimensional pop to the set design. If the box is strong enough, you can string up a piece of yarn along the back of the box and hang different backdrops from it using small clothespins or paper clips.
Add curtains. Cut a piece of fabric or velvet the same size as the display window or opening. Cut the fabric in half vertically to create the split between the two curtains. Glue the curtains in place or string yarn across the opening and wrap the curtains over the yarn, gluing to make the fold over the yarn. Use ribbons to tie the curtains back.
Consider special effects. If you want lighting effect, punch holes in the top of the puppet theater so that you can shine a goose neck lamp through the openings and into the finger puppet theater. You can shine light from below by cutting a hole from the bottom of the back of the puppet theater and shining a flashlight through.