Gather LEGO bricks and take an inventory of the types of bricks and type of character pieces you have. Looking at the available bricks can help inspire you to decide on the subject matter of your vignette. Mixing bricks from multiple predesigned LEGO sets will increase your options.
Plan out your vignette before building. A sketch of the final product will make the construction of the set easier, and ensure the most eye-pleasing final product.
Construct the characters for your vignette. Mix and match the body pieces and accessories of your bodies to make unique characters.
Build the scenery for your LEGO vignette using your LEGO bricks. For example, if creating a medieval vignette you can construct a castle wall and moat for your characters to fight on.
Place your LEGO characters onto the set to create a still piece which tells a story. For the example, knights dressed in two different sets of colors placed on a bridge over a moat depict a story of one army defending a castle against an invading force.