if your project is on Hindi and its history, then i would show photos of their culture. Photos that catch the eye and are interesting. show lots of color (the main colors that are used in Hindi). and throw in some interesting details of history that you covered. if you don't have photos of the specific details of history, then have an artistic friend draw it out for you.
I would imagine this depends on the project. For instance, if your project makes use of some power, you can use an LED light strip to make things more colorful, but you cannot use the lights if you are doing a project on processes like diffusion or osmosis.