Applying shellac depends on what the shellac is being used on. To apply shellac to furniture, one needs to remember that shellac is not durable and dissolves over time. Shellac comes in two colors, white and orange. Shellac also comes in different cuts. The most common of these cuts is 4 pound. Instructions for applying shellac to furniture can be found at http://tlc.howstuffworks.com/home/guide-to-furniture-finishes-ga3.htm.