When you start a project, always get reference first. This will guide you through the process. You can go back to an image and ask yourself how do I make that, or I like this style, or that looks a certain way. Without reference your guessing. Don't. Real world video, real world items are used as reference to go beyond and make imaginary seem Real. How does granite or marble look like in real life? How does a fruit look? Use google images, or bing, or youtube. Some images can inspire also.